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Does moderate drinking reduce heart failure risk?

Tue, 20/10/2015 - 12:10

"Seven alcoholic drinks a week can help to prevent heart disease," the Daily Mirror reports. A US study suggests alcohol consumption up to this level may have a protective effect against heart failure.

This large US study followed more than 14,000 adults aged 45 and older for 24 years. It found those who drank up to 12 UK units (7 standard US "drinks") per week at the start of the study had a lower risk of developing heart failure than those who never drank alcohol.

The average alcohol consumption in this lower risk group was about 5 UK units a week (around 2.5 low-strength ABV 3.6% pints of lager a week).

At this level of consumption, men were 20% less likely to develop heart failure compared with people who never drank, while for women it was 16%.

The study benefits from its large size and the fact data was collected over a long period of time.

But studying the impact of alcohol on outcomes is fraught with difficulty. These difficulties include people not all having the same idea of what a "drink" or "unit" is.

People may also intentionally misreport their alcohol intake. We also cannot be certain alcohol intake alone is giving rise to the reduction in risk seen.

Steps you can take to help reduce your risk of heart failure – and other types of heart disease – include eating a healthy diet, achieving and maintaining a healthy weight, and quitting smoking (if you smoke).

 

Where did the story come from?

The study was carried out by researchers from Brigham and Women's Hospital in Boston, and other research centres in the US, the UK and Portugal.

It was published in the peer-reviewed European Heart Journal.

The UK media generally did not translate the measure of "drinks" used in this study into UK units, which people might have found easier to understand.

The standard US "drink" in this study contained 14g of alcohol, and a UK unit is 8g of alcohol. So the group with the reduced risk actually drank up to 12 units a week.

The reporting also makes it seem as though 12 units – what is referred to in the papers as "a glass a day" – is the optimal level, but the study cannot not tell us this.

While consumption in this lower risk group was "up to" 12 units per week, the average consumption was about 5 units per week. This is about 3.5 small glasses (125ml of 12% alcohol by volume) of wine a week, not a "glass a day".

And the poor old Daily Express got itself into a right muddle. At the time of writing, its website is actually running two versions of the story. 

One story claims moderate alcohol consumption was linked to reduced heart failure risk, which is accurate. 

The other story claims moderate alcohol consumption protects against heart attacks, which is not accurate, as a heart attack is an entirely different condition to heart failure.

 

What kind of research was this?

This was a large prospective cohort study looking at the relationship between alcohol consumption and the risk of heart failure.

Heavy alcohol consumption is known to increase the risk of heart failure, but the researchers say the effects of moderate alcohol consumption are not clear.

This type of study is the best way to look at the link between alcohol consumption and health outcomes, as it would not be feasible (or arguably ethical) to randomise people to consume different amounts of alcohol over a long period of time.

As with all observational studies, other factors (confounders) may be having an effect on the outcome, and it is difficult to be certain their impact has been entirely removed.

Studying the effects of alcohol intake is notoriously difficult for a range of reasons. Not least is what can be termed the "Del Boy effect": in one episode of the comedy Only Fools and Horses, the lead character tells his GP he is a teetotal fitness fanatic when in fact the opposite is true – people often misrepresent how healthy they are when talking to their doctor.

 

What did the research involve?

The researchers recruited adults (average age 54 years) who did not have heart failure in 1987 to 1989, and followed them up over about 24 years.

Researchers assessed the participants' alcohol consumption at the start of and during the study, and identified any participants who developed heart failure.

They then compared the likelihood of developing heart failure among people with different levels of alcohol intake.

Participants came from four communities in the US, and were aged 45 to 64 years old at the start of the study. The current analyses only included black or white participants. People with evidence of heart failure at the start of the study were excluded.

The participants had annual telephone calls with researchers, and in-person visits every three years.

At each interview, participants were asked if they currently drank alcohol and, if not, whether they had done so in the past. Those who drank were asked how often they usually drank wine, beer, or spirits (hard liquor).

It was not clear exactly how participants were asked to quantify their drinking, but the researchers used the information collected to determine how many standard drinks each person consumed a week.

A drink in this study was considered to be 14g of alcohol. In the UK, 1 unit is 8g of pure alcohol, so this drink would be 1.75 units in UK terms.

People developing heart failure were identified by looking at hospital records and national death records. This identified those recorded as being hospitalised for, or dying from, heart failure.

For their analyses, the researchers grouped people according to their alcohol consumption at the start of the study, and looked at whether their risk of heart failure differed across the groups.

They repeated their analyses using people's average alcohol consumption over the first nine years of the study.

The researchers took into account potential confounders at the start of the study, including:

  • age
  • health conditions, including high blood pressure, diabetes, coronary artery disease, stroke and heart attack
  • cholesterol levels
  • body mass index (BMI)
  • smoking
  • physical activity level
  • educational level (as an indication of socioeconomic status)

 

What were the basic results?

Among the participants:

  • 42% never drank alcohol
  • 19% were former alcohol drinkers who had stopped
  • 25% reported drinking up to 7 drinks (up to 12.25 UK units) per week (average consumption in this group was about 3 drinks per week, or 5.25 UK units)
  • 8% reported drinking 7 to 14 drinks (12.25 to 24.5 UK units) per week
  • 3% reported drinking 14 to 21 drinks (24.5 to 36.75 UK units) per week
  • 3% reported drinking 21 drinks or more (36.75 UK units or more) per week

People in the various alcohol consumption categories differed from each other in a variety of ways. For example, heavier drinkers tended to be younger and have lower BMIs, but be more likely to smoke.

Overall, about 17% of participants were hospitalised for, or died from, heart failure during the 24 years of the study.

Men who drank up to 7 drinks per week at the start of the study were 20% less likely to develop heart failure than those who never drank alcohol (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.68 to 0.94).

Women who drank up to 7 drinks per week at the start of the study were 16% less likely to develop heart failure than those who never drank alcohol (HR 0.84, 95% CI 0.71 to 1.00).

But at the upper level of the confidence interval (1.00), there would be no actual difference in risk reduction.

People who drank 7 drinks a week or more did not differ significantly in their risk of heart failure compared with those who never drank alcohol.

Those who drank the most (21 drinks per week or more for men, and those drinking 14 drinks per week or more for women) were more likely to die from any cause during the study.

 

How did the researchers interpret the results?

The researchers concluded that, "Alcohol consumption of up to 7 drinks [about 12 UK units] per week at early middle age is associated with lower risk for future HF [heart failure], with a similar but less definite association in women than in men."

 

Conclusion

This study suggests drinking up to about 12 UK units a week is associated with a lower risk of heart failure in men compared with never drinking alcohol.

There was a similar result for women, but the results were not as robust and did not rule out the possibility of there being no difference.

The study benefits from its large size (more than 14,000 people) and the fact it collected its data prospectively over a long period of time.

However, studying the impact of alcohol on outcomes is fraught with difficulty. These difficulties include people not being entirely sure what a "drink" or a "unit" is, and reporting their intakes incorrectly as a result.

In addition, people may intentionally misreport their alcohol intake – for example, if they are concerned about what the researchers will think about their intake.

Also, people who do not drink may do so for reasons linked to their health, so may have a greater risk of being unhealthy.

Other limitations are that while the researchers did try to take a number of confounders into account, unmeasured factors could still be having an effect, such as diet.

For example, these confounders were only assessed at the start of the study, and people may have changed over the study period (such as taking up smoking). 

The study only identified people who were hospitalised for, or died from, heart failure. This misses people who had not yet been hospitalised or died from the condition.

The results also may not apply to younger people, and the researchers could not look at specific patterns of drinking, such as binge drinking.

Although no level of alcohol intake was associated with an increased risk of heart failure in this study, the authors note few people drank very heavily in their sample. Excessive alcohol consumption is known to lead to heart damage.

The study also did not look at the incidence of other alcohol-related illnesses, such as liver disease. Deaths from liver disease in the UK have increased 400% since 1970, due in part to increased alcohol consumption, as we discussed in November 2014.

The NHS recommends that:

  • men should not regularly drink more than 3-4 units of alcohol a day
  • women should not regularly drink more than 2-3 units a day
  • if you've had a heavy drinking session, avoid alcohol for 48 hours

Here, "regularly" means drinking this amount every day or most days of the week.

The amount of alcohol consumed in the study group with the reduced risk was within the UK's recommended maximum consumption limits.

But it is generally not recommended that people take up drinking alcohol just for any potential heart benefits. If you do drink alcohol, you should stick within the recommended limits.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Seven alcoholic drinks a week can help to prevent heart disease, new research reveals. Daily Mirror, January 20 2015

A drink a day 'cuts heart disease risk by a fifth' researchers claim...so don't worry about having a dry January. Mail Online, January 19 2015

A drink a night 'is better for your heart than none at all'. The Independent, January 19 2015

Glass of wine a day could protect the heart. The Daily Telegraph, January 20 2015

Daily drink 'cuts risk' of middle-age heart failure. The Times, January 20 2015

Drinking half a pint of beer a day could fight heart failure. Daily Express, January 20 2015

Links To Science

Gonçalves A, Claggett B, Jhund PS, et al. Alcohol consumption and risk of heart failure: the Atherosclerosis Risk in Communities Study. European Heart Journal. Published online January 20 2015

Categories: NHS Choices

Body clock may have effect on sporting peak performance

Fri, 30/01/2015 - 11:40

"Our internal body clock has such a dramatic impact on sporting ability that it could alter the chances of Olympic gold," BBC News reports.

This headline comes from a study of 20 female athletes, which showed their peak performance on a fitness test was strongly linked to what are described as "circadian phenotypes".

These phenotypes were assessed using a questionnaire that looked at issues such as the time people tended to wake up and what times of the day they felt most active.

Depending on the results of the questionnaire, they were then classified into one of three groups: morning types (larks), intermediate types (let's call them "afternooners"), and evening types (owls).

They were then asked to take part in a fitness test known as the bleep test at different times of the day to see if there was a pattern in terms of peak performances.

And there was: the larks peaked around 12:00, the afternooners peaked around 16:00, and the owls peaked around 20:00.

Despite media reports to the contrary, this study wasn't saying anything about whether exercising at different times of the day is better for your health.

As an aside, there is a theory these results could explain the historical underachievement of the England football team.

Their body clocks have been set to play at 15:00 on a Saturday afternoon, but most World Cup games take place around 17:00 or 20:00. This is pure speculation at this stage, but good ammunition for post-match punditry.

Any form of exercise, whatever time of the day, brings important health benefits.

 

Where did the story come from?

The study was carried out by researchers from the University of Birmingham. No funding source was mentioned in the publication.

It was published in the peer-reviewed science journal, Current Biology.

The reporting on the BBC and Mail Online websites was generally accurate, and included a lot of comment from the study authors about the possible wider implications of their research, such as how Spanish footballers may have an advantage in the UEFA Championship League because they are more used to playing in the evening.

However, both of the news sources' headlines were misleading. The BBC said that, "Bedtime 'has huge impact on sport'," but the research wasn't concerned with when people went to bed: it focused on whether people were generally morning or evening types.

The Mail, on the other hand, said: "Morning jog? Leave it until noon" – but this advice only applies to larks, and only really if they are aiming to set a new personal best.

 

What kind of research was this?

This was an experimental study looking at how peak athletic performance is related to the time of day and people's individual circadian rhythms.

Circadian rhythms are biological cycles in the body related to the time of day. They are sometimes referred to as "the body clock", or as the body's "individual biological timing".

Historically, people have been categorised as "larks" or "owls". Larks – morning people – rise early, are most active in the morning, and feel awake shortly after they get up. However, they feel tired come late afternoon or early evening.

By contrast, owls – or evening types – don't feel fully awake until many hours after they get up. They remain somewhat tired during the morning hours, but become active and switched on in the evenings.

The researchers tell us circadian rhythms have been linked to athletic performance in past research, alongside many other factors.

They also tell us athletes appear to perform at their best in the evening. They wanted to explore whether this held true if you took account of whether people were larks or owls, or somewhere in the middle.

The study was small and designed to test a new hypothesis: a proof of concept study. It was not designed to provide definitive proof athletic performance is affected by the time of day, or is related to a person's biological clock. It was not large enough or diverse enough to achieve these aims.

 

What did the research involve?

The Birmingham study team recruited 20 competition-level female hockey players and asked them to perform their best at the bleep test.

This is a test of cardiovascular fitness involving a series of 20m runs in shorter and shorter times. Researchers performed the test at six different times of day between 07:00 and 22:00 to see how their performance varied.

Meanwhile, the women completed a new questionnaire specifically designed to study sleep/wake-related parameters, training, competition, and performance variables in athletes.

The team used the answers to categorise the women into:

  • early circadian phenotype – "larks"
  • late circadian phenotype – "owls"
  • intermediate circadian phenotype – people more in the middle ("afternooners")

The analysis was pretty straightforward and appropriate.

 

What were the basic results? Analysis by time of day, ignoring circadian phenotype

Overall, the results showed peak performance on the bleep test was in the late afternoon, around 16:00 and 19:00. Performance was lowest at 07:00. The variation between the best and worst performance throughout the day was 11.2%.

Analysis by time of day, taking circadian phenotype into account

When the team looked more closely at peak performance, they found it was significantly influenced by circadian phenotype. They found:

  • larks peaked around 12:00
  • intermediate types peaked around 16:00
  • owls peaked around 20:00

The gap between the best and worst performance, when separated out by circadian phenotype, was 26% in the owls. It was less in larks (7.6% variation) and intermediates (10.0%)

To put this into context, the researchers reported the variation in time performance between first and seventh place at the 2012 London Olympic Games 100m sprint men's final was less than 5%.

They found peak performance was more related to the time people got up – specifically, the delay between that and competition – than the actual time of day.

Again, this varied a lot by circadian phenotype. Owls needed much longer after waking (around 11 hours) than larks before peak performance could be produced.

 

How did the researchers interpret the results?

The researchers stated the highlights of the research were findings that:

  • athlete performance shows significant daytime variation
  • personal best performance times differ significantly between circadian phenotypes
  • internal biological time is the most reliable predictor of peak performance time
  • daytime performance variations can be as pronounced as 26% in the course of a day

They concluded circadian rhythms, or internal biological time, are major determinants of athletic performance at different times of the day.

 

Conclusion

This study of 20 female athletes showed peak performance on a fitness test was linked to underlying biological timing, or what is called circadian phenotype. This was a better predictor of peak performance than the actual time of day.

The possible implications of the results were discussed widely in the media. Opinions ranged from a possible explanation for why Spanish teams do well in the Champions League (they must be full of evening types, which helps them perform best in the evening matches), to advice not to jog in the morning. A lot of this was speculative, so should be taken with a pinch of salt for now. 

There is also potential confusion about what this means for people currently exercising and wanting to keep healthy. For clarity: this study didn't say exercising at different times of day is better for your health and fitness.

It says if you are competing, you may perform your best at different times of day, and this depends on whether you are more of a morning or an evening person.

Advice to ditch the morning jog until noon espoused in the Daily Mail doesn't really follow from this research, unless the aim of your morning jog is to break a personal best.

Similarly, this study isn't particularly relevant for people exercising to lose weight. It's more useful for athletes and coaches looking to optimise competitive performance.

The study authors advise internal biological time is more important than time of day, and we should listen to and understand the body clock more.

It would be interesting to know whether the circadian phenotype can be changed so, for example, athletes can prepare their bodies better for competition at a set time of day, even if this doesn't naturally fit with their lark/owl status. This study didn't address this question, but other related research might.

The study was small, only included women, and was designed mainly to show proof of concept. A larger, more diverse group (including men, for example) would need to be studied for us to be confident these results are applicable to the majority of athletes.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Bedtime 'has huge impact on sport'. BBC News, January 30 2015

Morning jog? Leave it until noon: Performance does not peak until several hours after a person has woken up. Mail Online, January 30 2015

Links To Science

Facher-Childs E, Brandstaetter R. The Impact of Circadian Phenotype and Time since Awakening on Diurnal Performance in Athletes. Current Biology. Published online January 29 2015

Categories: NHS Choices

Child obesity rates are 'stabilising'

Fri, 30/01/2015 - 11:00

"The rise in childhood obesity … may be beginning to level off," BBC News reports. Researchers examined trends in child and adolescent rates of overweight and obesity using electronic GP records from 1994 to 2013.

The data shows there was a significant increase in child and adolescent overweight and obesity rates every year during the first decade from 1994 to 2003. Overall, annual rates did not increase significantly during the second decade, 2004 to 2013.

However, when split by age category, the results showed there was still a significant upward trend in overweight and obesity rates for the oldest age group (11 to 15 years) – albeit with less of an increase than there was in the first decade. At its maximum in recent years, overweight and obesity has affected almost two-fifths of adolescents in this age group.

As the researchers used GP records, it is possible children who have problems with their weight and were assessed by their GP are over-represented. This could then lead to an overestimate of prevalence. However, it is hard to think of another method of analysis that would provide a more reliable estimate.

While it is encouraging to see that the child obesity epidemic is not getting worse, there are also no clear signs as yet that it's getting any better. Underlying factors, such as low activity levels and easy access to calorie-rich, nutrient-poor foods, still remain to be addressed.

 

Where did the story come from?

The study was carried out by researchers from King's College London, and was funded by the National Institute of Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London.

It was published in the peer-reviewed BMJ group publication, Archives of Disease in Childhood. The article is available on an open access basis, so it is free to read online or download.

Overall, the UK media coverage is generally accurate, though sources have a different take on the research – some pointing out the good news, others the bad.

The Daily Mail's statement that the "crisis at its worse among 11 to 15-year-olds" is not wholly accurate. While overweight and obesity rates in this age group have still increased in the past decade, it has been to a lesser extent than previously. It is also difficult to say that now is the "crisis point" as such, as we don't know what's going to happen in the future.

 

What kind of research was this?

This was a population-based cohort study that aimed to use GP electronic health records in England to examine the prevalence of overweight and obesity in children and adolescents aged 2 to 15 years. Researchers looked at data from 1994 to 2013 to see how trends have changed over the past two decades.

Obesity has become a significant public health issue in both adults and children, with rates in children known to have increased dramatically over past decades.

However, the researchers say there have been recent reports suggesting that obesity levels in children may have levelled off. That is what this study aimed to look at.

The main limitation of such a study is being able to sample a group of children that represent a fair picture of the child population as a whole.

Being based on database records, the study is not going to have information, or up-to-date information, on all children and adolescents. However, it should give a good representation of general trends.

 

What did the research involve?

The research used information from the Clinical Practice Research Datalink (CPRD), a large database holding the electronic health records of about 7% of general practices in the UK – about 5.5 million people. The coverage of GPs in the database was reported to be broadly representative of geographic distribution in the UK.

The CPRD contains information on weight, height and body mass index (BMI) where this has been collected. Only the first BMI recording for a child was taken for any given year, though an individual child could contribute several years' worth of data.

The final analysis included data from 370,544 children who contributed 507,483 BMI observations across the two study decades (average 1.4 BMI observations per child).

The researchers analysed BMI by sex and by three different age groups (2 to 5 years, 6 to 10 years, and 11 to 15 years). They looked at trends over the two decades 1994 to 2003, and 2004 to 2013. Thirty-nine per cent of the collected data came from the first decade, 61% from the second.

 

What were the basic results?

The prevalence of children who were either overweight or obese ranged as follows:

For boys:
  • 2-5-year-old boys – minimum 19.5% prevalence in 1995, to maximum prevalence 26.0% in 2007
  • 6-10-year-old boys – minimum 22.6% in 1994, to maximum 33.0% in 2011
  • 11-15-year-old boys – minimum 26.7% in 1996, to 37.8% in 2013
For girls:
  • 2-5-year-old girls – minimum 18.3% in 1995, to maximum 24.4% in 2008
  • 6-10-year-old girls – minimum 22.5% in 1996, to maximum 32.2% in 2005
  • 11-15-year-old girls – minimum 28.3% in 1995, to maximum 36.7% in both 2004 and 2012

Looking at annual trends, there was a clear year by year increase in prevalence of overweight and obesity in the first decade (1994 to 2003), with less of an annual increase in the second decade (2004 to 2013).

Looking at the odds of a child being overweight or obese, the annual increase in risk across every year of the study was 4.2%.

However, when broken down by decade, the annual risk increase was 8.1% between 1994 and 2003, but only 0.4% between 2004 and 2013.

The increase in risk of overweight or obesity each year was significant in the first decade, but not in the second. The researchers say this indicates overweight and obesity rates are stabilising. These trends were similar with separate analyses for both boys and girls.

When looking at trends per age category, the risk of overweight and obesity increased significantly every year for all age groups in the first decade between 1994 and 2003.

During the second decade, the risk of overweight and obesity did not increase significantly each year for the two younger age groups.

However, for the oldest age group (11 to 15 years), there was still a significant annual increase in risk of overweight and obesity during the second decade (by 2.6%), though this was still much smaller than the annual increase in the first decade (12%).  

When looking specifically at obesity, all trends were comparable to those for the combined category of overweight and obesity as outlined above.

 

How did the researchers interpret the results?

The researchers say the use of GP electronic health records in England may provide a valuable resource for monitoring trends in obesity.

They say that, "More than a third of UK children are overweight or obese, but the prevalence of overweight and obesity may have stabilised between 2004 and 2013."

 

Conclusion

This research shows how trends in child and adolescent overweight and obesity have changed over the two decades from 1994 to 2013, as indicated by GP records.

As the results show, for both boys and girls, the prevalence of overweight and obesity increases with increasing age category, with the highest prevalence recorded in the 11 to 15-year-old age group, which at its maximum has affected almost two-fifths of adolescents in recent years.

However, it is encouraging to see that while there were significant annual increases in child overweight and obesity rates in the first decade between 1994 and 2003, the overall annual increase was not significant during the second decade, 2004 to 2013.

But when split by age category, it does show there was still a significant upward trend in overweight and obesity rates for the oldest age group (11 to 15 years), albeit with less of an increase than there was in the first decade.

Therefore, as the researchers say, this still highlights the need for interventions to address overweight and obesity, particularly for this adolescent age group.

An important limitation to be aware of for this study, though, is the possibility of selection bias. The study has used a large GP electronic database holding height and weight information for more than 350,000 children in the UK. It needs to be considered how representative this sample may be of the general child and adolescent population the UK.

While the database does contain a representative sample of GP practices and their registered population, not all UK children in these age groups will have been to the GP and had their height and weight measured.

There is the possibility a child may have been more likely to have their height and weight measured (particularly in successive years) if there have been problems with their weight.

As such, it is possible the database could be over-representative of children with weight issues, and so give an overestimate of the prevalence of overweight and obesity in the general child and adolescent population of the UK.

But accessing reliable data that is representative of every person is clearly not feasible, and using a reliable GP electronic database should give us a reasonable indication of the likely prevalence in the UK.

Such a study also can only provide us information on trends. It can't tell us the reasons that may be behind these changing trends, or tell us of future ones.

While the results suggest overweight and obesity levels may be levelling off (at least among the younger age groups), this is not to say they will now start to decrease. There have been annual decreases in the past, for example, that weren't sustained.

Overweight and obesity levels could still remain at these relatively high levels of around a third of all children and adolescents, or increase further again unless things change.

These results may give some encouragement, but childhood overweight and obesity remains an important public health issue. The various possible influences of overweight and obesity, such as low activity levels and consumption of calorie-dense food and drink, still need to be addressed. 

The study is likely to lead to further calls by public health campaigners for the introduction of legislation designed to tackle childhood obesity, such as a curb on advertising and a tax on unhealthy foods.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Child obesity rates 'levelling off' among under-10s. BBC News, January 30 2015

Fat Britain: A third of children are now officially overweight with crisis at its worse among 11 to 15-years-olds. Daily Mail, January 30 2015

Childhood obesity epidemic may be 'levelling out,' claims new study. The Independent, January 30 2015

Child Obesity 'Levelling Off' But Concerns Remain. Sky News, January 30 2015

One in four teens now obese by 15. The Daily Telegraph, January 30 2015

More than a THIRD of children are obese but the problem is FINALLY slowing down. Daily Mirror, January 30 2015

Over a third of children in England overweight. ITV News, January 30 2015

Links To Science

van Jaarsveld CHM, Gulliford MC. Childhood obesity trends from primary care electronic health records in England between 1994 and 2013: population-based cohort study. Archives of Disease in Childhood. Published online January 29 2015

Categories: NHS Choices

A third of over-70s report 'frequent sexual activity'

Thu, 29/01/2015 - 11:00

“A third of pensioners have sex at least twice a month,” the Daily Mail reports. A new UK study reinforces the point that sex doesn’t automatically stop once a person gets their free bus pass.

The study looked at sexual activity and sexual health among more than 6,000 men and women aged 50 to 90. It showed that a sizeable minority of older people – including those over the age of 80 – continue to have active sex lives, although sex became less frequent as people got older.

Men were particularly concerned about their sexual health as they got older, while women became less so. Men were worried about erection problems and women about lack of desire.

This is an interesting study of sexuality among older people. It relies on self-reporting, which might undermine its reliability, as some people may find it hard to be honest about such a sensitive topic.

A final important point is that sexually transmitted infection (STIs) don’t stop being a problem once you have retired. Recent data has shown that rates of common STIs in the 65 and over category have risen in England during the past decade. You should always practise safe sex whatever your age. 

 

Where did the story come from?

The study was carried out by researchers from the University of Manchester, University of Leeds and NatCen Social Research. It was funded by the National Institute on Aging and a consortium of UK government departments.

The study was published in the peer-reviewed journal Archives of Sexual Behavior.

The Daily Mail’s report that one third of pensioners have sex at least twice a month was accurate, but the results of this study were more complex than the Mail’s report implied as it was not all good news.

Many participants expressed concerns about sex, not just the frequency of their sexual activity. Also, the study did not cover only “pensioners” but people aged 50 and over.

 

What kind of research was this?

This was an observational study of sexual activity, problems with sexual functioning and concerns about sexual health among 6,201 older adults in England. The authors point out that stereotypes of older people often ignore the significance of sexual activity. Specifically how sexual activity, or lack of it, can affect fulfilment in relation to quality of life and emotional wellbeing. Also little is known about how sexuality relates to the ageing process generally.

 

What did the research involve?

The researchers used data from a nationally representative survey of men and women in England aged 50 years and older, who were taking part in an ongoing longitudinal study of ageing (the English Longitudinal Study of Ageing). All participants were living in the community, in private households, so the study did not cover older people in residential care.

In 2012/13, 7,079 participants had a face-to-face interview and completed a comprehensive questionnaire on their sexual relationships and activities. Partners under 50 were excluded and 6,201 participants, 56% of them women, were included in the final sample.

The questionnaire included detailed questions on attitudes to sex, frequency of sexual activities, problems with sexual activities and function, concerns and worries about sex, and details about current sexual partnerships. 

Participants were also asked about their current living arrangements and general health and lifestyle factors during the face-to-face interview. They were asked if they had ever been diagnosed with any of several common conditions, including high blood pressure, arthritis, cardiovascular diseasediabetes and asthma.

They were also asked to rate their:

  • health on a five point scale (ranging from excellent to poor),
  • smoking status (current or non-smoker)
  • frequency of alcohol consumption over the past year (ranging from never or rarely, to frequently – three days a week to almost every day)

Depressive symptoms were also assessed using a validated depression scale.

The researchers analysed their results, looking specifically at any association between sexual activity, reported chronic conditions and self-rated general health. They adjusted results for age, partner status, smoking status and frequency of alcohol consumption.

 

What were the basic results?

Below are the main findings of the study:

  • At all ages, men reported more frequent sexual activity and thinking about sex more often than women. Likewise, sexually active men reported higher levels of concern with their sexual health and sexual dissatisfaction than women at all ages.
  • Levels of sexual activity declined with increasing age, although a sizable minority of men and women remain sexually active until the eighth and ninth decades of life.
  • Poorer health was associated with lower levels of sexual activity and a higher prevalence of problems with sexual functioning, particularly among men.
  • The difficulties most frequently reported by sexually active women related to becoming sexually aroused (32%) and achieving orgasm (27%), while for men the main difficulty was erectile function (39%).
  • The sexual health concerns most commonly reported by women related to their level of sexual desire (11%) and frequency of sexual activities (8%). Among men common concerns were level of sexual desire (15%) and erectile difficulties (14%).
  • While the likelihood of reporting sexual health concerns tended to decrease with age in women, the opposite was seen in men.
  • Poor sexual functioning and disagreements with a partner about initiating and/or feeling obligated to have sex were associated with greater concerns about and dissatisfaction with overall sex life.

 

How did the researchers interpret the results?

The researchers say that their study shows many older people, including those over 80, continue to have active sex lives, although the frequency of sexual activities declines with increasing age.

Women appeared less dissatisfied with their overall sex life than men and reported decreasing levels of dissatisfaction with increasing age.

They say that older people’s sexual health should be “managed” not just in the context of their age, gender and general health, but also within their existing sexual relationship.

 

Conclusion

This study suggests not only that many older people are still sexually active, but that, like every other age group, they have worries and concerns about sex and relationships. Not surprisingly, ageing and failing health affect sexual activity.

Older men report worrying about getting erections, while women are more concerned with lack of desire. The study also reminds us that sexual problems have to be seen in the context of a relationship.

The study is, by definition, based on people self reporting on sex, which might undermine its reliability. It is possible that some people find it hard to be honest about such a sensitive area, even in a confidential questionnaire.

If you are an older adult and you are having problems with your sex life then there may be treatment options available. Read more about how you could have a fulfilling sex life as you get older.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Sex in your 70s? Absolutely! A third of pensioners have sex at least twice a month, study finds. Daily Mail, January 29 2015

Links To Science

Lee DM, Nazroo J, O’Connor DB, et al. Sexual Health and Well-being Among Older Men and Women in England: Findings from the English Longitudinal Study of Ageing. Archives of Sexual Behavior. Published online January 27 2015

Categories: NHS Choices

Thousands of UK women could benefit from 'three-person' IVF

Thu, 29/01/2015 - 11:00

"Thousands of women could benefit from 'three-parent' baby technique," The Independent reports. A modelling study estimated the technique, which is currently illegal, could be used for thousands of women with genes linked to serious mitochondrial DNA diseases.

The news is especially topical as it was announced today that parliament is set to vote in February about whether to make the technique legal.

"Three-parent" IVF is designed to prevent babies being born with mitochondrial conditions. Mitochondria are the "powerhouses" within our cells that convert sugar into energy.

A baby inherits its mitochondria from its mother, and women with mutations in their mitochondrial DNA are at risk of passing on a mitochondrial genetic disorder to their offspring.

Mutations in mitochondrial DNA can cause a range of disorders affecting the muscles, heart, brain and eyes. Some children can be severely affected and have a reduced life expectancy. There is currently no cure.

The new techniques use healthy mitochondria from a donor egg to replace the mitochondria in the mother's egg, either before fertilisation or just after, to prevent passing on mutations.

While on a technical level a baby conceived in this way would have three "parents", in practice only 1% of genetic information would come from the third "parent" (the egg donor).

The modelling study attempted to estimate the number of women in the UK and US who could benefit from such techniques. This aims to help inform decisions around whether the technique should be allowed.

The study estimated 2,473 women in the UK could benefit from the new IVF technique. This was based on the proportion of women known to be at risk in the north east of England, so does not take into account variations across the UK or US in terms of ethnic diversity or average maternal age.

As this technique is untried, it is currently unknown how effective it may be, or what the short- or long-term consequences are.

 

Where did the story come from?

The study was carried out by researchers from Newcastle University.

It was funded by the Wellcome Trust Centre for Mitochondrial Research, the Newcastle University Centre for Ageing and Vitality, the Medical Research Council, the Lily Foundation, the UK National Institute for Health Research, and the UK NHS Specialist Commissioners Rare Mitochondrial Disorders of Adults and Children Service.

The study was published as a letter in the peer-reviewed New England Journal of Medicine on an open-access basis, so it is free to read online.

The UK media reporting was accurate, though it wasn't pointed out we still do not know how effective or safe the techniques might be.

 

What kind of research was this?

This study aimed to estimate how many women in the UK and US might benefit from new IVF techniques that use donor mitochondria (sometimes referred to as "three-parent" IVF). These techniques aim to prevent women passing mitochondrial mutations on to their offspring.

The researchers based these estimations on data on how many women have a mitochondrial DNA (mtDNA) mutation and whether this affects their fertility.

As these techniques are not currently legal, before they can be used they require new regulations to be passed in parliament regarding the Human Fertilisation and Embryology Act (1990).

In simple terms, the new techniques involve either:

  • taking the DNA from the nucleus of the egg that has just been fertilised (most of our DNA is found in the nucleus) and transferring it to a donor egg that has had the nuclear DNA removed, but still has the healthy mitochondria and mtDNA
  • taking the mother's DNA from the nucleus of her egg and inserting it into a donor egg that has had its nuclear DNA removed, but still has healthy mtDNA intact – fertilisation would then take place using the donor egg and father's sperm

Behind the Headlines discussed these techniques in more detail back in June 2014.

These techniques are controversial – at present, it is against the law to modify DNA before or after fertilisation because of concerns about the ethics of changing people's DNA in a way that will be inherited in generations to come.

Indeed, no country in the world has passed regulations for these techniques to be used. Because of this, it is important that the health, social, ethical and legal implications are considered fully before any decisions are made.

Still, it is worth considering that similar concerns were raised when IVF was first introduced in the late 1970s, and it is now considered standard practice.

As this technique looks like a promising way to avoid certain diseases, the Department of Health put out a public consultation in February 2014 on whether these techniques should be allowed to be used. Following the responses received, parliament is set to vote on the issue in February 2015.

 

What did the research involve?

The number of women in the UK and US who have the potential to pass on an mtDNA mutation was first estimated. This was based on the percentage of women of childbearing age who have been identified in the north east of England as having mtDNA mutations, as well as their fertility rate.

The researchers used data from the UK Office for National Statistics to calculate fertility rate in the general population. They then compared this with data on women who are carriers of a disease-causing mtDNA mutation from the MRC Mitochondrial Disease Cohort UK to see if fertility is affected by these mutations.

They also had local data from the north east of England on the proportion of women who had an mtDNA mutation. They used these figures to estimate the likely number of women affected in the rest of the UK and US.

 

What were the basic results?

Fertility rates were not reduced in women with a disease-causing mtDNA mutation. The researchers identified 154 women with such mutations from the MRC Mitochondrial Disease Cohort, and found their fertility rate was 63.2 live births per 1,000 person-years, compared with 67.2 in the general population.

They say that in women most severely affected, the rate was 50.6 live births per 1,000, compared with a similar group of women in the general population with a rate of 52.6 live births per 1,000.

Based on this, the estimated number of childbearing-age women at risk of passing on a mitochondrial disease was:

  • 2,473 women in the UK
  • 12,423 women in the US

 

How did the researchers interpret the results?

The researchers concluded if all women in the UK estimated to have an mtDNA mutation wanted to have a child and had the new IVF procedure, this could benefit 150 births per year.

 

Conclusion

This study has provided an estimate of the number of women of childbearing age who might pass on an mtDNA mutation to their offspring. The researchers say this is nearly 2,500 women in the UK and could affect 150 births per year.

However, as the authors point out, the estimates do not take into account the following factors, which vary across the UK and US, compared with the north east of England:

  • average age of women giving birth
  • ethnic diversity
  • actual number of women with a mitochondrial DNA mutation

The researchers also acknowledged that even if the new regulations are passed, not all women would necessarily have access to the new IVF technique, or would want it.

As these new IVF techniques are not currently legal, they have not resulted in the birth of any babies conceived using them. It is therefore not known how effective the techniques might be, or what the short- or long-term consequences are.  

The Department of Health put out a public consultation on whether these two techniques should be allowed to be used in February 2014. Following the responses, parliament is set to vote on the issue in February this year.

It is difficult to predict the outcome of the vote. At the time of writing, there has been no official party whip announced by the various political parties on how their MPs should vote.

Most commentators expect it to be a free vote, where MPs are left to vote according to their own personal beliefs, which makes it even harder to predict.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Thousands of women could benefit from 'three-parent' baby technique. The Independent, January 28 2015

150 babies a year could be born to three-parent families: Children with DNA from two eggs and one sperm could be saved from potentially lethal genetic diseases. Mail Online, January 28 2015

Legalise three-parent babies, say Nobel winners. The Times, January 29 2015

Links To Science

Gorman GS, Grady JP, Ng Y, et al. Mitochondrial Donation – How Many Women Could Benefit? New England Journal of Medicine. Published online January 28 2015

Categories: NHS Choices

Sugary soft drinks linked to earlier periods in girls

Wed, 28/01/2015 - 11:30

“Sugary drinks may cause menstruation to start earlier, study suggests,” reports The Guardian, reporting on a US study looking at the consumption of sugar-sweetened beverages (SSBs) in teenage girls.

This study included over 5,000 girls. It first assessed them when they were aged 9-14 years, asking them whether they had started their periods and assessing their consumption of SSBs. The girls were followed up annually.

The study found that girls in the highest consumption category (more than 1.5 SSB servings per day) were 22% more likely to start their period in the next month than girls in the lowest consumption category (two or fewer SSB servings per week). Girls in this highest consumption category started their periods at an average age of 12.8 years, which was 2.7 months earlier than girls in the lowest consumption category.

However, this study does not prove that SSB consumption is the direct cause of this difference, as many unmeasured health and lifestyle factors may be influencing the relationship.

One potential concern is that an early onset of menstruation (menarche) has been linked to an increased risk of some types of cancer, such as breast cancer. However, even if SSBs have a direct effect on menarche, cancer outcomes were not assessed by this study. It is uncertain whether the small difference seen, which is just a few months, would have any meaningful effect on later risk of breast cancer.

Overall, people should not be overly concerned, though the limitations of this study do not take away from the fact that SSBs are high in sugar and calories. Sugar can lead to tooth decay, and a high intake of sugar and calories can lead to obesity.

 

Where did the story come from?

The study was carried out by researchers from Harvard School of Public Health and Harvard Medical School, and was funded by the Breast Cancer Research Foundation, the National Institute of Environmental Health Sciences and National Institutes of Health, among other sources. The study was published in the peer-reviewed medical journal Human Reproduction on an open-access basis, so it is free to read online or download as a PDF.

The media correctly reported the association between fizzy drinks and earlier age of starting periods, but some headlines, such as The Daily Telegraph’s suggestion that such drinks “cause early puberty”, are unproven.

In addition, The Telegraph’s and the Daily Mirror’s headlines that the drinks “increase [sic] cancer risk in girls” may cause undue alarm. It is important to highlight that the study has not looked at cancer outcomes, either in girls or when they grow into women. This headline purely relates to the fact that the earlier age of starting periods is recognised as a risk factor – among many others – for cancers such as breast and endometrial (womb) cancer.

 

What kind of research was this?

This was an analysis of data collected in a prospective cohort study that aimed to see whether SSB consumption in girls is associated with the age when their periods start (menarche).

The researchers used participants of “The Growingup Today Study”, a prospective cohort study of children of participants in the US Nurses’ Health Study II. The researchers say how age at menarche is known to have decreased considerably in the Western world over the past couple of centuries. They say that the association of later menarche with calorie restriction and earlier menarche in children with a higher body mass index (BMI) supports the importance of nutritional factors. Previous studies are said to have investigated the link between protein intake and menarche, but the link with many other food groups remains unstudied. The researchers were interested in SSBs due to increase in popularity over the same time period in which age at menarche has decreased.

The main limitation of an analysis such as this is the potential for other health and lifestyle factors to be affecting age at menarche. In addition, The Growingup Today Study was not designed specifically to answer the current question, so may not have been able to measure all factors that might have been considered, if this was the main aim.

 

What did the research involve?

The Growingup Today Study included 9,033 girls, 5,227 of whom had data available for inclusion in this study.

A baseline questionnaire was given in 1996 when the girls were aged 9-14 years, with annual follow-up questionnaires up until 2001. In 1996, ‘97 and ’98, a 132-item questionnaire for young people and adolescents assessing what they ate and drank (a food frequency questionnaire) was given to the participants. They were asked how often they consumed a typical serving size of specified foods and drinks during the past year. For drinks, the serving size was one can/glass for soda and diet soda, one glass for non-carbonated fruit drinks (including Hawaiian Punch, lemonade, Koolaid and other non-carbonated fruit drinks), and one glass/can/bottle for sweetened iced tea. Total consumption of SSBs were calculated as the sum of these drinks. The total did not include diet soda or non-fizzy fruit juice, which were assessed separately.

Each follow-up questionnaire asked whether the girls had started their periods, and when.

The researchers calculated how the likelihood of menarche over time for girls in each category of SSB consumption compared with girls who drank the least SSBs (two or fewer servings per week). They adjusted for total energy intake and various other potential confounders, including physical activity, BMI, birthweight, ethnicity, mother’s age at menarche, family composition, and eating meals together as a family.

 

What were the basic results?

The average (median) age at menarche in this study was 13.1 years. Girls who drank more SSBs were more likely to have an earlier menarche.

After adjustment for all confounders, girls at any age between 9 and 18.5 years who had not yet started their periods were on average 22% more likely to start their periods in the following month if they drank the most SSBs (more than 1.5 SSB servings per day, equivalent to more than 10.5 servings per week) than girls who drank the least SSBs (2 or fewer SSB servings per week; hazard ratio (HR) 1.22, 95% confidence interval (CI) 1.11 to 1.35).

Girls who drank the most SSBs started their period at an average age of 12.8 years of age, which was 2.7 months earlier than girls who drank the least SSBs.

Looking at individual drinks, drinking the highest amounts of non-fizzy fruit drinks and sugar-sweetened fizzy drinks were associated with increased risk of starting menarche compared to the lowest consumption of these drinks. However, consumption of fruit juice or diet fizzy drinks did not affect age at menarche.

 

How did the researchers interpret the results?

The researchers conclude that, “more frequent SSB consumption was associated with earlier menarche in a population of US girls”. They acknowledge that though they adjusted for a variety of possible confounders, there is still the chance that factors other than SSB consumption are influencing the results. They also say that they did not measure SSB consumption during early childhood, which may also affect age at menarche.

 

Conclusion

People should not be overly concerned by this study’s findings, as they cannot prove that drinking SSBs directly causes earlier puberty in girls – they can only show a link.

Also, the difference between girls who drank the most SSBs in terms of when they started their period was an average of just 2.7 months earlier than girls who drank the least, which seems a relatively small difference.

There are various limitations to this study – not least the possibility that the results are being influenced by confounding, which the researchers acknowledge. Nutrition is already known to play a role in the timing of first periods, with higher BMI and calorie intake linked to earlier periods. Though they have tried to adjust for these and other factors that could be having an effect (including physical activity), there is still the possibility that their effect or those of other factors have not been removed. It is difficult to know how much of a direct and independent effect – if any – SSBs could be having.

Other points of limitation include that the possibility of inaccurate recall of SSB consumption and that the assessments may not be representative of longer-term consumption patterns. The first assessments were taken when the girls were around the age of 9-14 years – a time when many girls will be starting their periods anyway. This also makes it difficult to establish any cause and effect relationship. As the researchers say, SSB consumption during earlier childhood may be an important time period that they have not measured.

The study results are also for a US population who may differ from the UK, both in terms of their SSB consumption, and other factors that may influence age at menarche.

Even if SSB consumption does cause earlier menarche, it is difficult to know what health effects, if any, this would have. While it is true that earlier menarche is recognised as one possible risk factor for breast cancer, for example, this study did not assess any health outcomes other than menarche.

It is uncertain how much of an impact the small time difference in age of menarche seen in this study could have on breast cancer risk. The authors state that previous research has suggested that a one year decrease in the age at menarche is thought to increase breast cancer risk by around 5%. Therefore, they consider the 2.7 month reduction in age to be only “modest”. There are also a wide range of other health and lifestyle factors associated with breast cancer risk, some of which (alone or in combination) may have a greater influence than age at menarche.

Nevertheless, whatever the limitations of this study, SSBs are by their nature high in sugar and calories. High intake could contribute to an increase in risk of overweight and obesity if the calories are not burned off. Overweight and obesity are associated with many detrimental effects upon health, and sugar can also lead to tooth decay in later life.

There is normally a non-sugar alternative available to the most popular SSBs.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Sugary drinks may cause menstruation to start earlier, study suggests. The Guardian, January 28 2015

Sugary drinks 'can bring on a girl's periods earlier': Youngsters who drink more than one a day begin puberty at younger age. Daily Mail, January 28 2015

Fizzy drinks cause early puberty and increases cancer risk in girls, study finds. The Daily Telegraph, January 28 2015

Soft drinks may cause girls to start their periods early, scientists say. Metro, January 27 2015

One and a half cans of fizzy drink a day raises breast cancer risk. Daily Mirror, January 28 2015

Links To Science

Carwile JL, Willett WC, Spiegelman D, et al. Sugar-sweetened beverage consumption and age at menarche in a prospective study of US girls. Human Reproduction. Published online January 27 2015

Categories: NHS Choices

Gift vouchers can help pregnant smokers quit

Wed, 28/01/2015 - 10:40

"Offering shopping vouchers worth a total of £400 to pregnant smokers makes them more likely to quit the habit, say researchers," BBC News reports.

The study, conducted in Glasgow, involved 612 pregnant women referred to pregnancy stop smoking services. The women were randomised to receive standard stop smoking care alone (control), or standard care in addition to up to £400 in vouchers if they successfully quit the habit.

The study found significantly more women in the voucher group (22.5%) stopped smoking by late pregnancy (34 to 38 weeks) compared with the control group (8.6%).

An obvious response to this – found in many news websites, as well as comments on message boards – is why should we bribe women to do what is best for their unborn baby?

A pragmatic answer to that question is it could save children's lives. Smoking during pregnancy is a major health problem estimated to cause the deaths of 5,000 unborn foetuses and babies each year in the UK, and costs the health system millions of pounds.

And the results of this study were within the range considered to be a cost effective use of healthcare resources.  

A caveat of the research, though, is those who took part in the study represented only one-fifth of all pregnant smokers. 

The way to reduce smoking among the apparent majority who do not wish to engage with stop smoking services, and may be less motivated to quit, is another problem.

Further studies in other parts of the UK are now needed to see if a national programme would be cost effective.

 

Where did the story come from?

The study was carried out by researchers from the University of Stirling, Glasgow University, and the University of Nottingham.

Funding was provided primarily by the Chief Scientist Office and the Scottish government, with additional funding from the Glasgow Centre for Population Health, the Education and Research Endowment Fund of the Director of Public Health Greater Glasgow and Clyde Health Board, the Yorkhill Children's Charity, and the Royal Samaritan Endowment Fund.

The study was published in the peer-reviewed British Medical Journal, and the article is open access, so it can be read for free online or downloaded as a PDF.

The media is generally representative of this research, and most coverage contains various discussions around the ethical aspects of financial incentives.

Interestingly, a comparable media response was seen after a similar – and apparently successful – voucher scheme hit the headlines, which we discussed in November 2014, where mothers were given vouchers if they committed to breastfeeding their baby.

 

What kind of research was this?

This was a phase II randomised controlled trial (RCT) that aimed to assess the effectiveness of adding a financial incentive to routine specialist stop smoking services for pregnant women to help them quit.

There are various stages of clinical trial that go towards demonstrating whether or not a particular treatment is safe and effective, and could possibly be appropriate for wider use.

Phase II trials follow on from phase I trials and include more people. They gather more evidence about whether the particular treatment is safe and if there are any side effects, who it is most effective for, and what's the best way to give treatment.

If phase II trials are successful, they lead on to larger phase III trials, which aim to demonstrate whether or not the treatment is effective compared with a control or another active treatment.

Smoking in pregnancy is associated with various adverse effects during pregnancy, including an increased risk of miscarriage, premature birth, low birthweight, and stillbirth, in addition to various maternal health effects.

The National Institute for Health and Care Excellence (NICE) has highlighted the need for evidence on the effectiveness of financial incentives. Recent studies have suggested financial incentives may help pregnant smokers stop, but more evidence is needed.

The researchers involved in this study carried out the RCT in a single centre in Glasgow to look at the acceptability and effectiveness of giving up to £400 of shopping vouchers, in addition to routine specialist pregnancy NHS stop smoking services, to help these women quit.

 

What did the research involve?

Pregnant women over the age of 16 were recruited from maternity booking clinics in Glasgow between December 2011 and February 2013. They were eligible if they reported they were smokers and special breath tests (carbon monoxide test) also indicated they were smokers.

All pregnant smokers were referred to specialist pregnancy stop smoking services. Women who agreed to take part in the trial were then randomly allocated to either receive up to £400 of shopping vouchers (staggered over time) if they engaged with services and subsequently quit smoking, in addition to routine stop smoking services or routine stop smoking services alone. 

Stop smoking services offer an initial one-hour appointment to discuss smoking and set a quit date, followed by four further support calls and free nicotine replacement treatment for 10 weeks. Smoking status was assessed four weeks, 12 weeks, and one year after the set quit date.

In the incentives group, people received £50 if they attended their initial appointment and set a quit date.

Those who reported not smoking at all for the past two weeks (abstinence) at the four-week point after their quit date were visited at home and took a breath test to confirm this.

Confirmed quitters received another £50 voucher. If 12 weeks later they had still quit, they received £100.

Women's smoking status was assessed again between 34 and 38 weeks of pregnancy, and £200 was given if they were confirmed to be abstinent.

Being abstinent at this stage was defined as the woman reporting not smoking, or smoking fewer than five cigarettes in the past eight weeks.

This was verified by testing the women's urine or saliva for the levels of a chemical called cotinine, which is increased in smokers.

The main outcome the researchers were interested in was quitting smoking in late pregnancy, at between 34 and 38 weeks.

Other outcomes included attendance for the initial appointment, not smoking four weeks after the quit date, quitting six months after birth (postnatally), and pregnancy outcomes (miscarriage, pre-term birth, low birthweight and stillbirth).

 

What were the basic results?

A total of 612 women agreed to participate in the trial – 306 were allocated to the financial incentive group and 306 to the control group.

This represented only 20% of all self-reported smokers who attended for a maternity booking during the study period (3,052 women), and 53% of those who got as far as being contacted by stop smoking services (1,150 women).

Significantly more women stopped smoking between 34 and 38 weeks in the incentive group (22.5%) than the control group (8.6%).

This was calculated as a more than doubled likelihood of stopping smoking by the end of the pregnancy with the financial incentive (relative risk [RR] 2.63, 95% confidence interval [CI] 1.73 to 4.01).

The researchers calculated this meant around 7 to 8 women would need to receive a financial incentive for one additional woman to stop smoking. Or, in more precise terms, the intervention had a number needed to treat (NNT) of 7.2.

Looking at other outcomes, incentives increased self-reported abstinence four weeks after the women's agreed quit dates, but had no effect on the percentage of women attending the initial engagement with stop smoking services or any of the birth outcomes.

 

How did the researchers interpret the results?

The researchers concluded that: "This phase II randomised controlled trial provides substantial evidence for the efficacy of incentives for smoking cessation in pregnancy."

They say that as it was only a single-centre trial, financial incentives should now be tested in different types of pregnancy cessation services in different parts of the UK.

 

Conclusion

This randomised controlled trial demonstrates that adding financial incentives to standard stop smoking services increases the proportion of women who stop smoking in late pregnancy.

The trial was well conducted, including regular contact with participants up to six months postnatally, and all self-reported smoking measures were checked with chemical tests.

The proportion of women who could not be followed up was also fairly low, and was the same in both groups (about 15%). The researchers assumed those who could not be followed up were still smokers in their analyses, which is appropriately cautious.

The study does demonstrate such schemes may be successful. As the researchers say, their study has only looked at services in Glasgow, and other studies would now be needed in other parts of the UK to see if the scheme works as well.

The study does raise some questions, though. Financial incentives were demonstrated to have more than doubled cessation rates by the end of pregnancy, but only among pregnant smokers who agreed to be referred to stop smoking services.

These were women who the services were able to contact through repeated calls and who then agreed to take part. In the end, this was only 20% of self-reported smokers who attended maternity bookings during this period.

The results therefore may not be representative of what could be achieved in the other 80% of pregnant smokers, who may be less motivated to quit.

Further study may benefit from exploring the reasons why some women may not engage with specialist pregnancy smoking services, and ways to reach greater numbers of women.

Another issue the researchers raise about these types of schemes is the potential for women to be untruthful if the outcomes are reliant on self-reported smoking status alone, without being verified through breath, blood and urine tests, as used in this trial context.

As they also say, it is possible the women in this study only stopped smoking temporarily around the time the measures were taken. Further study therefore may be needed looking at the issue of unreliable reporting around real smoking status in pregnancy.

Some may also be concerned about the potential extra financial strain these schemes could put on the NHS. The researchers report the extra cost for each extra quitter who had stopped smoking by late pregnancy was £1,127 – as well as the actual vouchers, there are administrative and staffing costs to take into account.

Additional calculations suggest the scheme would represent good value for money for the NHS, based on the thresholds usually used.

Financial incentives for health behaviour change are always going to be controversial: "Public perceptions of 'paying' individuals to change behaviour can be negative," the researchers acknowledged. But they report a public opinion survey conducted as part of a related study deemed such schemes acceptable.

Whatever opinions and ethical considerations there may be around financial incentives, smoking during pregnancy remains a major health problem – estimated to cause the deaths of 5,000 unborn foetuses and babies each year in the UK – and is currently responsible for millions of pounds of healthcare spending. These factors need to be balanced, and it clearly remains an important and sensitive area to be addressed.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Vouchers 'boost quit rates' in pregnant smokers. BBC News, January 28 2015

£400 bribes to help pregnant women stop smoking: Mothers-to-be twice as likely to quit if they have a financial incentive. Daily Mail, January 28 2015

Pay pregnant women to quit smoking, study says. The Independent, January 27 2015

Pregnant women will quit smoking if you offer them shopping vouchers worth £400, according to study. Metro, January 28 2015

More pregnant women give up smoking if paid, say researchers. ITV News, January 28 2015

Pregnant smokers more likely to quit with financial incentive. Daily Express, January 28 2015

Links To Science

Tappin D, Bauld L, Purves D, et al. Financial incentives for smoking cessation in pregnancy: randomised controlled trial. BMJ. Published online January 27 2015

Categories: NHS Choices

Female lung cancer deaths 'may outstrip breast cancer' in 2015

Tue, 27/01/2015 - 12:12

The Mail Online states: “Lung cancer death rates among European women set to overtake breast cancer for first time this year,” adding that “researchers blame high levels of smoking, especially in Britain and Poland”.

The study used historical information on deaths from cancer (1970 to 2009) for the EU, to predict the number of deaths in 2015. It also did this for some individual countries, including the UK.

The overall results from the study were arguably positive. Cancer death rates for the EU have been declining in most cancers and are likely to continue declining in 2015. However, this masked less positive trends in specific cancer types, specific countries, and differences between men and women.

What hit the headlines was the prediction that lung cancer deaths in women will rise. The lung cancer death rate would be the highest of all cancer types for women, exceeding that of breast cancer for the first time.

The study didn’t investigate the reasons for the lung cancer mortality trend, but said that smoking was the likely culprit. Women who took up the habit in the past are likely to be now reaching the age where the cumulative effects of tobacco smoke will mean that approximately half of them will be killed by their habit.

Quitting smoking is likely to be the single biggest thing you can do to improve your health and many people don’t find it that difficult. Read our stop smoking advice.

 

Where did the story come from?

The study was carried out by researchers from universities based in Italy and Switzerland, and was funded by the Swiss League against Cancer, the Swiss Foundation for Research against Cancer, the Italian Association for Cancer Research and COST Action EU-Pancreas.

The study was published in the peer-reviewed medical journal Annals of Oncology. The study is free to view and download online.

The media coverage was generally balanced and included useful information on the potential explanations for the high rates of smoking in UK women.

The Mail Online quoted lead researcher Professor Carlo La Vecchia as saying, “This is due to the fact that British women started smoking during the Second World War, while in most other EU countries women started to smoke after 1968. It is worrying that female lung cancer rates are not decreasing in the UK, but this probably reflects the fact that there was an additional rise in smoking prevalence in the UK as well in the post-1968 generation – those born after 1950”.

 

What kind of research was this?

The research was an ecological study estimating the number of cancer cases across Europe for 2015, based on past trends.

The report’s authors wanted to update previous predictions for the EU made in 2012 and to explore prostate cancer, the third largest cause of male cancer deaths in the EU, in more depth.

An ecological study is good at estimating what happens at a wide geographic level to large groups of people. The drawback is that it cannot tell us what will happen to any one person. We could say that more women in the UK will probably die from lung cancer in 2015 than 2009, but we can’t say, based on this type of study, who will.

 

What did the research involve?

The researchers fed a statistical model with sets of historical data on stomach, colorectal, pancreas, lung, breast, uterus, prostate, cancers of the white blood cells, and total cancers from across the EU. The model estimated what cancer rates would be like in 2015, based on the previous trends.

Estimates of death rates by age group and gender were calculated for the EU as a whole, and individually for its most populous countries of France, Germany, Italy, Poland, Spain and the UK.

The data for the EU as a whole covered a period from 1970 to 2009. The UK-specific data was up-to-date as of 2010.

Data were obtained from the World Health Organization and Eurostat – both publically available sources of European statistics. These sources rely on official death certificate data, as well as population level estimates.

 

What were the basic results?

The overall picture was that cancer rates have been falling in the EU and in the UK since the 1970s, and that this trend is likely to continue overall. However, this masks a number of increasing trends for specific types of cancer, and differences between men and women.

Predicted overall cancer deaths in the EU for 2015

More than a million cancer deaths were predicted in the EU in 2015 (766,200 men and 592,900 women), corresponding to standardised death rates of 138.4 per 100,000 men and 83.9 per 100,000 women. Comparing 2009 data to 2015, total cancers are predicted to fall by 7.5% in men and 6% for women.

Pancreatic cancer had a negative outlook in both sexes, rising by 4% in men and 5% in women between 2009 and 2015.

Predicted female cancer deaths in the EU for 2015

In women, breast and colorectal cancers had favourable downward trends (-10% and -8%), but predicted lung cancer rates are set to rise 9% to 14.24 deaths per 100,000 women, becoming the cancer with the highest rate, reaching, and possibly overtaking, the breast cancer rate.

The total number of deaths predicted for 2015 remain higher for breast (90,800) than lung (87,500).

Predicted male cancer deaths in the EU for 2015

In men, predicted rates for the three major cancers in 2015 were lower than in 2009, with prostate falling by 12%, lung cancer by 9% and colorectal by 5%.

Prostate cancer showed estimated falls of 14%, 17% and 9% in the 35-64, 65-74 and over-75 age groups.

 

How did the researchers interpret the results?

The overall conclusions of the researchers were that: “Cancer mortality predictions for 2015 confirm the overall favourable cancer mortality trend in the EU, translating to an overall 26% fall in men since its peak in 1988, and 21% in women, and the avoidance of over 325,000 deaths in 2015, compared with the peak rate”.

 

Conclusion

This ecological study used historical information on deaths from cancer for the EU region (1970 to 2009) to predict the numbers of deaths in 2015.

The overall news was positive: cancer death rates for the EU have been declining in most cancers and are likely to continue declining in 2015. However, this masked other less positive trends in specific cancer types, specific countries, and differences between men and women.

The predictions that hit the headlines were that lung cancer deaths in women are going to rise. Moreover, that the rates (number of deaths per 100,000 women) would be the highest of all cancer types for women, knocking breast cancer off the top spot for the first time.

The study did not investigate the potential causes for the lung cancer death increases directly, but the likely culprit is smoking, which is one of the biggest risk factors for developing lung cancer. Women who took up the habit in the past are now reaching the age where the cumulative effects ensure that approximately half of them will be killed by their habit.

As with all ecological studies, these results cannot predict local variations in cancer rates or whether any specific individuals will get cancer. For example, there may be some areas in the UK where women’s lung cancer rates are actually declining, contrary to the EU or overall UK trend, whereas in others they may be increasing more rapidly than predicted. More focused data will help us when targeting public health resources to areas most in need.

Quitting smoking is likely to be the single biggest thing you can do to improve your health, and many people don’t find it that difficult. There are a number of proven aids to increase the chance of you beating the habit.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Lung cancer death rates among European women set to overtake breast cancer for first time this year. Mail Online, 27 January 2015

Lung cancer fatalities to overtake breast cancer deaths among European women. The Guardian, 27 January 2015

More British women now die from lung cancer than breast cancer. Daily Miror, 26 January 2015

Links To Science

Malvezzi M, et al. European cancer mortality predictions for the year 2015: does lung cancer have the highest death rate in EU women? Annals of Oncology. Published 26 January 2015

Categories: NHS Choices

Media dementia scare over hay fever and sleep drugs

Tue, 27/01/2015 - 09:54

"Hay fever tablets raise risk of Alzheimer's," is the main front page news in the Daily Mirror. The Guardian mentions popular brand names such as Nytol, Benadryl, Ditropan and Piriton among the pills studied.

But before you clear out your bathroom medicine cabinet, you might want to consider the facts behind the (somewhat misleading) headlines.

The first thing to realise is although some of these drugs can be bought over the counter, the study only included prescribed medicines.

These were medicines that have an "anticholinergic" effect, including some antihistamines, antidepressants and drugs for an overactive bladder.

If you have been prescribed these medicines, do not stop taking them without speaking to a doctor first. The harms of stopping might outweigh any potential benefits.

That said, this large, well-designed US study suggested those taking the highest levels of anticholinergic prescribed medicines were at a higher risk of developing dementia compared with those not taking any.

Importantly, the increased risk was only found in people who took these medicines at the equivalent of once every day for more than three years. No link was found at lower levels.

However, this shouldn't make us complacent. These are not unrealistic doses of medicines, so the results may be applicable to a significant proportion of older adults.

Furthermore, we can't say if reducing the amount of anticholinergic medicines will reduce the risk of dementia to normal.

The bottom line? Do not stop taking prescribed medications without a full consultation with a doctor. It may do more harm than good.

 

Where did the story come from?

The study was carried out by researchers from the University of Washington.

It was funded by the National Institute on Aging, the National Institutes of Health, and the Branta Foundation.

The study was published in the peer-reviewed medical journal, JAMA Internal Medicine.

A number of the study's authors reported receiving research funding from pharmaceutical companies, including Merck, Pfizer and Amgen.

The story made almost all the newspapers and many online and broadcast services, with front page "splash" stories in the Mirror and The Times.

This coverage lacked the necessary caution and has all the hallmarks of a media scare story.

The media reporting of the study generally took the findings at face value and did not highlight the potential risks associated with stopping medications suddenly.

On Radio 4 this morning, one of the study authors advised people to stop taking these types of medicines.

This is potentially dangerous, and we do not support this advice. Any changes to prescribed medicines should be made after full consultation with a medical professional and should factor in your individual circumstances.

Poor media reporting also included:

  • Failing to mention the study was based on prescribed drugs, rather than those bought over the counter – an error made by the Mirror and The Daily Telegraph.
  • Failing to make it clear the antihistamines involved were only one, older class known to cause drowsiness (and avoided by many people because of this) – a mistake made by The Times, The Independent and the Mail.
  • Naming a brand (Benadryl) focused on by researchers that has a completely different drug in it in the UK – a mistake made by The Times, the Mail, The Independent and The Telegraph.
  • Having headlines that didn't make it clear the association was only seen in people over the age of 65 – a mistake made by most papers, except The Times.
  • Playing fast and loose with statistics – the Mail said up to 50% of elderly people could be taking an anticholinergic, a statement so vague it could mean half of them take them, or none take them.

Today, the Mirror, with its front page "Shocking new report" headline, was perhaps the most overblown coverage, although it was among one of the most factually correct.

The Telegraph also did well to include suggestions for alternative antihistamines and antidepressants that could be used by over-65s.

 

What kind of research was this?

This was a prospective cohort study looking at whether the use of medicines that have anticholinergic effects are linked to dementia or Alzheimer's disease.

Medications with anticholinergic effects are commonly used for a wide variety of conditions affecting older adults, such as an overactive bladder. 

Some of these medications can be bought over the counter, such as antihistamines like chlorphenamine – which is mainly sold under the brand name Piriton and is not to be confused with other antihistamine products, such as Piriteze – and sleeping pills, such as diphenhydramine, sold under the Nytol brand.

The study authors stated the prevalence of anticholinergic use in older adults ranges from 8% to 37%.

A prospective cohort study cannot definitively prove this drug class causes Alzheimer's disease or dementia, but it can show they are linked in some way. Further research is needed to properly investigate and explain any links identified.

 

What did the research involve?

The research team analysed data on 3,434 US people aged over 65. These people had no dementia at the start of the study.

The study's participants were tracked for an average of 7.3 years to see who developed dementia or Alzheimer's disease.

The researchers also gathered information on what anticholinergic medications they were prescribed in the past.

The researchers' main analysis looked for statistically significant links between these prescribed medications taken in the past 10 years and the likelihood of developing dementia or Alzheimer's disease.

Cases of dementia and Alzheimer's were first picked up using a test called the Cognitive Abilities Screening Instrument, which was given every two years.

This was followed up with investigations by a range of specialist doctors, and laboratory tests, to arrive at a consensus diagnosis.

Medication use was ascertained from a computerised pharmacy dispensing database that included the name, strength, route of administration (such as in tablets or in syrup), date dispensed, and amount dispensed for each drug. This was linked to each individual's US health insurance plan so it was personalised.

Prescriptions in the most recent one-year period were excluded because of concerns about bias. This bias could occur when a medication is inadvertently prescribed for early signs of a disease that has not yet been diagnostically detected. For instance, medications may be prescribed for insomnia or depression, which can be early symptoms of dementia.

Drugs with a strong anticholinergic effect were defined as per an American Geriatrics Society consensus panel report. Data for the medicines was converted into an average daily dose, and this was added up over the number of years people were taking them to estimate their total cumulative exposure.

This cumulative exposure was defined as cumulative total standardised daily doses (TSDDs).

The statistical analysis adjusted for a range of potential confounders identified from past research, including:

  • demographic factors such as age, sex, and years of education
  • body mass index
  • whether or not they smoked
  • their exercise levels
  • self-rated health status
  • other medical problems, including hypertension, diabetes, stroke, and heart disease
  • whether they had a variant of the apolipoprotein E (APOE) gene
  • Parkinson's disease
  • high levels of depressive symptoms
  • cumulative use of benzodiazepine medicines – this could indicate a sleep or anxiety disorder

 

What were the basic results?

The most common anticholinergic classes used over the long term were antidepressants, antihistamines, and bladder control medicines.

During an average (mean) follow-up of 7.3 years, 797 participants (23.2%) developed dementia. Most people diagnosed with dementia (637 of the 797, 79.9%) had Alzheimer's disease.

Overall, as cumulative anticholinergic exposure over 10 years increased, so did the likelihood of developing dementia, including Alzheimer's disease. Results were reported to stand up to secondary analyses.

For dementia, cumulative anticholinergic use (compared with no use), was associated with:

  • for TSDDs of 1 to 90 days, a confounder adjusted hazard ratio (HR) of 0.92 (95% confidence interval [CI], 0.74-1.16) 
  • for TSDDs of 91 to 365 days 1.19 (95%CI, 0.94-1.51)
  • for TSDDs of 366 to 1,095 days 1.23 (95%CI, 0.94-1.62)
  • for TSDDs of more than 1,095 days 1.54 (95% CI, 1.21-1.96)

It is important to note the only statistically significant result was in the group with the highest long-term exposure level.

At standardised cumulative doses of between 1 and 1,095 days (three years), there was no statistically significant increase in incidence of dementia compared with those with no exposure.

However, those in the highest cumulative anticholinergic exposure group were 54% more likely to develop dementia compared with those with no anticholinergic exposure over the previous 10-year period.

 

How did the researchers interpret the results?

The researchers' conclusions were grounded, and warned of a potential risk if the results were true. They said that, "Higher cumulative anticholinergic use is associated with an increased risk for dementia.

"Efforts to increase awareness among healthcare professionals and older adults about this potential medication-related risk are important to minimise anticholinergic use over time."

 

Conclusion

This large US prospective cohort study suggests a link between those taking high levels of anticholinergic medicines for more than three years and developing dementia in adults over 65.

The main statistically significant finding was in a group taking the equivalent of any of the following medications daily for more than three years:

  • xybutynin chloride, 5mg
  • chlorpheniramine maleate, 4mg
  • olanzapine, 2.5mg
  • meclizine hydrochloride, 25mg
  • doxepin hydrochloride, 10mg

These are not unrealistic doses of medicine, so the results may be applicable to a significant proportion of older adults.

The main limitations of the research were recognised and openly discussed by the study authors. Although we don't expect them to have significantly biased the results, we cannot rule out the possibility.

These limitations include the potential misclassification of "exposure". This is possible because some anticholinergic medicines are available without a prescription – called "over-the-counter" medicines. These would have been missed in this study, which relied on a database of prescribed medicines only.

It is therefore possible people who were reported to have no exposure may actually take, for example, regular doses of Piriton for hay fever without needing a prescription.

A related point is there is no guarantee the prescribed medications were actually taken – although it is likely they were, especially in the groups in the higher exposure categories.

Finally, we don't know whether these results can be generalised to other groups of people. The study sample was overwhelmingly white (91.5%) and university educated (66.4%). The findings will need replication in studies that recruit larger and more diverse participants to reflect wider society.

Studies are needed to better understand whether any increase in dementia risk is counteracted after people stop using anticholinergic medicines.

While there are biologically plausible theories, the mechanism by which anticholinergics might contribute to dementia risk is not well understood.

It is important to realise this study was about prescribed medicines. If you have been prescribed anticholinergic medicines, do not stop taking them without speaking to your GP first as everyone's circumstances are different. The harms of stopping might outweigh any potential benefits.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Study suggests sleeping drugs can increase risk of Alzheimer’s. The Guardian, 27 January 2015

Popular sleep remedies and hay fever pills 'increase risk of Alzheimer's by more than 50%'. Daily Mail, 26 January 2015

Hay fever and sleeping tablets 'can increase risk of Alzheimer's and dementia'. Daily Mirror, 26 January 2015

Routine drugs for elderly ‘raise risk of dementia’. The Times, 26 January 2015

Hayfever pills and sleeping aids can 'significantly increase' risk of Alzheimer’s, says US study. The Independent, 26 January 2015

Hayfever drugs raise risk of Alzheimer's disease, say scientists. The Daily Telegraph, 27 January 2015

Dementia 'linked' to common over-the-counter drugs. BBC News, 27 January 2015

Links To Science

Gray SL, et al. Cumulative Use of Strong Anticholinergics and Incident Dementia. A Prospective Cohort Study. JAMA Internal Medicine. Published 26 January 2015

Categories: NHS Choices

People with autism have 'unique' brain patterns

Mon, 26/01/2015 - 11:40

"The brains of people diagnosed with autism are 'uniquely synchronised'," the Mail Online reports.

Researchers used brain scans to study the brain activity of people with high-functioning autism spectrum disorders (ASD), and found distinct and differing patterns of connectivity in adults with high-functioning ASD compared with adults who do not have the condition.

This headline is based on a study comparing resting functional magnetic resonance imaging (fMRI) scans in 141 people with or without high-functioning ASD.

High-functioning ASD tends to be the term used when people have the characteristic features of autism, such as difficulties with social interaction, but without the intellectual impairment that is classically seen.

The study found communication between different areas of the brain at rest in people with high-functioning ASD differs from that of adults without ASD. In some areas, there is more communication going on, and in other areas there is less.

The exact patterns of communication differed between different people with high-functioning ASD, and people with more differences seemed to have higher levels of ASD symptoms.

We cannot say whether these differences are the cause or a result of ASD, as all of the individuals already had the condition at the time of the brain scan.

It is not yet clear whether this finding will help with diagnosing ASD earlier, as the study did not test this.

 

Where did the story come from?

The study was carried out by researchers from the Weizmann Institute of Science in Israel and Carnegie Mellon University in the US.

It was funded by an Israeli Presidential Bursary, the Simons Foundation, the Pennsylvania Department of Health, the European Union, the Israel Science Foundation, Israeli Centers of Research Excellence, and the Helen and Martin Kimmel award.

The study was published in the peer-reviewed journal, Nature Neuroscience.

It isn't possible to say whether the Mail Online's suggestion that the findings "may help earlier diagnosis" will be the case.

 

What kind of research was this?

This was a cross-sectional study comparing the brains of adults with high-functioning ASD and adults without ASD.

ASD is the term used for developmental conditions characterised by difficulties with social interaction (such as difficulties in picking up on the emotions of others), communication (such as problems holding a conversation), and having a restricted or repetitive collection of interests or set routines and rituals.

Individuals with typical autism tend to have these features in addition to some degree of intellectual impairment.

Individuals with high-functioning autism or Asperger's syndrome tend to have normal or enhanced intellectual ability.

When we are at rest, our brains still send signals (messages) within each half (hemisphere) of the brain, and between the hemispheres.

In the past, there have been suggestions people with ASD have less signalling (communication) going on between different parts of the brain at rest than people without ASD.

However, recent studies suggest the opposite might be true. The researchers in this study wanted to resolve this by looking at more information on brain activity in people with high-functioning ASD, and those without ASD.

The design of this study is appropriate for comparing brain signalling in people with high-functioning ASD and without ASD. However, it cannot say whether these differences are the cause or a result of the ASD.

 

What did the research involve?

The researchers used a database of resting brain scans from adults with high-functioning ASD and adults without ASD. They compared the level of communication going on between and within the hemispheres, and in more specific regions of the brain, to see if there were any differences.

The resting brain scans were obtained using fMRI. The scans were from the Autism Brain Imaging Data Exchange (ABIDE) database, which stores resting fMRI brain scans of people with ASD and controls (people without ASD) for research purposes.

The data used in the current study was collected at a range of US universities. For some individuals, the data available also included measures of IQ and the individuals' behavioural symptoms, using the Autism Diagnostic Observation Schedule (ADOS) for symptoms in adulthood, and the Autism Diagnostic Interview (ADI) for childhood history of ASD.

The study only included people classified as having high-functioning ASD according to these scales.

The individuals whose data was analysed had an average age of around 26 years, and were mostly male (91% of those with ASD and 81% of those without).

There were 141 people in the main brain connection analyses (68 with ASD and 73 without), but not all had all of the information available on symptoms, for example. 

 

What were the basic results?

The researchers found there was greater communication between some regions of the brain in adults with high-functioning ASD than those without ASD, but less communication between others.

This essentially meant those with high-functioning ASD showed a different pattern of resting communication in their brain from the typical pattern seen in people without ASD.

This pattern also showed differences between different individuals with high-functioning ASD – so not all people with this diagnosis had the same pattern of brain signalling at rest.

The researchers found the more the communication between the reciprocal areas in the two halves of the brain differed from the "typical" pattern, the more severe behavioural symptoms the person with ASD tended to have as an adult, using the ADOS scale (total scores).

The brain differences did not appear to be related to measures of childhood history of ASD (ADI scores) or IQ scores.

 

How did the researchers interpret the results?

The researchers say their findings suggest there are different spatial patterns in the connection patterns seen in the brains of people with high-functioning ASD at rest, in comparison with people who do not have the condition.

They say these connection differences could be used to measure brain differences and symptom severity in people with ASD. They also explain why previous studies have conflicting findings about the amount of signalling in the brains of people with ASD.

 

Conclusion

This study suggests resting brain communication in people with high-functioning ASD differs from that of adults without ASD. In some areas, there is more communication going on, and in other areas there is less.

In addition, the exact pattern of communication differs between different people with high-functioning ASD.

This may explain why different studies of brain activity in people with ASD have had different findings in the past. The level of differences also seems to be related to the level of symptoms a person has.

The researchers say more research is needed to see whether the resting brain connection differences seen in people with high-functioning ASD represent the extreme end of a range of differences seen in the general population.

This is particularly important, as only a relatively small number of controls were assessed, and this may not capture the full range of brain communication across people without ASD.

The researchers note they could not control for differences across the sites where data was collected – for example, how the data was compiled.

However, they say the robustness of their findings is supported by how the potential differences distorted the patterns of connections across the different sites in the brain scans of people with high-functioning ASD.

They also only used data from adults with high-functioning ASD and processed the data using the same techniques to try to reduce variability.

It's important to note we cannot say whether these differences are the cause or a result of the ASD. The results are also only applicable to adults with high-functioning ASD, and may not apply to children or people with ASD who are not in the "high-functioning" category.

At the moment, we don't know whether this information could help make a diagnosis of ASD earlier, as this study did not look at this. More studies would be needed to determine whether this is the case.

Despite being a relatively common condition, affecting around 1 in 100 people, the cause(s) of ASD remain unclear. It is thought several complex genetic and environmental factors are involved.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

People with autism show 'unique brain patterns', say scientists who believe discovery may help earlier diagnosis. Mail Online, January 23 2015

Links To Science

Hahamy A, Behrmann M, Malach R. The idiosyncratic brain: distortion of spontaneous connectivity patterns in autism spectrum disorder. Nature Neuroscience. Published online January 19 2015

Categories: NHS Choices

Brown fat may protect against diabetes and obesity

Mon, 26/01/2015 - 10:30

"Fat can protect you against obesity and diabetes," the Mail Online reports. However, the small study it reports on was looking at brown fat, which is only found in small amounts in adults.

In humans, brown fat is mostly found in newborns, who are more prone to heat loss and are unable to shiver to help keep themselves warm. Brown fat compensates by burning calories to create heat. As we grow older, we have less need for brown fat and it is mostly replaced by white fat ("bad fat").

The current study involved just 12 men. It looked at whether men with detectable levels of brown fat differed from men who didn't in terms of how their bodies dealt with sugar, particularly in cold conditions.

The researchers wanted to see what happened when the men were exposed to cold over five to eight hours.

The researchers found that, when exposed to the cold over five to eight hours, only the men with brown fat showed an increase in the energy they were burning and how fast they used up the sugar circulating in their blood.

This has led to the idea the effect could in some way be harnessed to help protect against type 2 diabetes or obesity.

However, any such advances are a long way off. This study was very small, only in men and, crucially, we cannot currently control the amount of brown fat we have.

Eating fatty foods will result in more white fat if you consume more calories than you burn off, and being overweight or obese increases your type 2 diabetes risk.

 

Where did the story come from?

The study was carried out by researchers from the Shriners Hospital for Children in Texas and other research centres in the US, Greece, Sweden, and Canada.

It was funded by the University of Texas Medical Branch, the National Center for Advancing Translational Sciences, the National Institutes of Health, the American Diabetes Association, Shriners Hospital for Children, the John Sealy Memorial Endowment Fund, the Claude D Pepper Older Americans Independence Center, and the Sealy Center on Aging.

One study author is a shareholder and consultant to Ember Therapeutics, a company that seems to work on treatments for type 2 diabetes and obesity by targeting brown fat. This represents a potential conflict of interest.

The study was published in the peer-reviewed medical journal, Diabetes.

The Mail Online covers this study reasonably well, pointing out early on that brown fat is not the type of fat you get from eating too many calories. However, it did not mention the small number of men in the study.

The suggestion from the study authors that, "This is good news for overweight and obese people" or those with diabetes probably overestimates the practical implications of these findings.

 

What kind of research was this?

This was an experimental study carried out in men with and without detectable brown fat. It aimed to see whether brown fat might influence how the body deals with sugar.

Brown fat generates heat to help keep the body's temperature constant. In humans, it is mostly found in newborns, who are unable to shiver and keep themselves warm.

As we grow we have less of a need for brown fat, so most is replaced by white fat. White fat differs from brown in that it stores energy for the body when we consume more calories than we burn off.

 

What did the research involve?

The researchers enrolled 12 healthy men for their study: seven with detectable brown fat and five without.

They then tested them at normal room temperatures (about 19C or 66.2F) and after five to eight hours of exposure to cold.

They looked at how much energy the men's bodies were burning at rest, and how their bodies were dealing with sugar and fat.

Participants were cooled by wearing a temperature-controlled vest and blanket, which gradually dropped in temperature until the participant was shivering and then raised in temperature by one degree. The participant was then kept at this temperature for five to eight hours.

At the start of the study, to check whether the man had detectable brown fat, their bodies were cooled and injected with a radioactively labelled glucose (a type of sugar).

Their bodies were then scanned using a positron emission tomography (PET) scan, which could identify where in the body the glucose was located.

As brown fat generates heat to help keep the body temperature stable, the idea was that as the men were cold, if they had brown fat, it would take up more glucose to make more heat.

This meant the researchers could see where the brown fat was in the body. They looked for brown fat specifically in the area just between the collar bone (clavicle) and the base of neck. They also took samples of tissue from this area to look for brown fat.

Men with and without brown fat were similar in their characteristics. Men without brown fat were slightly older (average 49.8 years versus 41.2 years).

Once the researchers knew which men had detectable brown fat and which did not, they then carried out a range of tests at normal temperature and at cold temperatures.

This included testing how much energy the men were burning at rest and how their bodies dealt with sugar and fat (fatty acids) infused into their bloodstreams. The normal temperature and cold temperature experiments were carried out two weeks apart.

During the study, the volunteers followed a controlled diet and wore standardised clothing to make them as comparable as possible.

 

What were the basic results?

The researchers found exposure to cold increased the amount of energy the men with brown fat were burning at rest. This was not the case for men without brown fat.

The extra energy being used up by the brown fat was coming from glucose and fatty acids being taken up from the blood.

Cold exposure increased the total amount of glucose being taken up by the cells of the body in men with brown fat, but not those without brown fat.

The researchers estimated brown fat could take up a considerable amount of glucose from the circulation and therefore could help control blood glucose levels.

This was also the case if the men were given insulin to reproduce what would happen after a meal. Insulin increased glucose uptake in both groups, but uptake was still higher in men with brown fat.

 

How did the researchers interpret the results?

The researchers concluded they found brown fat has a significant impact on the ability of the whole body to dispose of glucose.

They say this supports a role for brown fat in controlling glucose levels and sensitivity to insulin in humans.

They suggest brown fat could be a target for combating obesity and diabetes if we can develop ways to activate brown fat in the body, or get white fat to behave more like brown fat.

 

Conclusion

This small experimental study has suggested that in healthy men, brown fat can increase the uptake of blood glucose by cells in response to cold, and increase the amount of energy being used up at rest.

Because of the small size of this study and the fact it only included healthy men, it is not possible to say whether the results are representative of the general population.

With such small numbers, there could have been other unmeasured differences between the groups (such as biological and lifestyle differences) that influenced the results, rather than just brown fat.

Other groups of people or other tests, rather than just this single experiment, could have given different results. Larger studies will be needed to confirm its findings.

The study also only looked for an indication of brown fat in one area of the body, and this may not be representative of the rest of the body.

These results do not have implications for the general public, as we currently cannot control the amount of brown fat we have. The excess calories we eat are stored as white fat rather than brown fat, and being overweight or obese increases the risk of diabetes rather than reducing it.

Even for those who happen to have brown fat, standing in the cold for prolonged periods is unlikely to be a practical long-term way to improve your glucose metabolism or energy consumption.

As the researchers say, investigations will undoubtedly continue into finding ways to capitalise on brown fat in the fight against obesity and diabetes, but we will need to wait to see whether this brings results.

Until then, the most effective method to reduce your diabetes risk is to try to achieve or maintain a healthy weight.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Fat can PROTECT you against obesity and diabetes, improving blood sugar control and metabolism, study finds. Mail Online, January 23 2015

Links To Science

Chondronikola M, Volpi E, Børsheim E, et al. Brown Adipose Tissue Improves Whole-Body Glucose Homeostasis and Insulin Sensitivity in Humans. Diabetes. Published online July 23 2014

Categories: NHS Choices

Statin use may be widening health inequalities in England

Fri, 23/01/2015 - 12:30

“Mass prescription of statins ‘will widen social inequalities’," The Independent reports. 

The headline is based on a new study looking at deaths from coronary heart disease in England from the years 2000 to 2007.

The good news is that overall deaths from heart disease were estimated to be down by a third (34.2%) during the time period.

The bad news, at least for those concerned about health inequalities, is that the use of statins (a cholesterol-lowering drug), benefitted the richest 20% more than the poorest 20% of society.

This is unlikely to be due to any biological factor and may instead arise due to a combination of socioeconomic and cultural reasons, such as people with chaotic lifestyles associated with poverty being less likely to stick to a treatment plan.

The study also found that population-based approaches – such as encouraging people to stop smokingeat a healthy diet and take regular exercise – have had a much bigger impact than medical approaches, like statins.

This led the study authors to suggest that there needs to be a greater emphasis on population-based approaches in the future, if we are not to see health inequalities widen further.

This study usefully informs debate in the public health sector about the best and fairest way of continuing this reduction in the future. 

 

Where did the story come from?

The study was carried out by researchers from the University of Liverpool, University of Chester, University College London, Public Health Wales and the University of British Columbia (Canada). It was funded by the National Institutes for Health Research School of Public Health Research and Liverpool PCT FSF scheme.

The study was published in the peer-reviewed medical journal BMJ Open. As the name suggests, this journal is open-access, meaning anyone can read that full article online for free.

Different UK newspapers emphasised different angles of the story (which seemed to be linked to their political editorial line), but they all covered the facts of the study accurately. 

 

What kind of research was this?

This was a modelling study trying to work out what proportion of a fall in coronary heart disease deaths in England was due to preventative medications, like statins, and what proportion was due to population-wide changes like diet and exercise. They were also interested in exploring the relative effects on different socioeconomic groups.

The UK, the study authors inform us, has experienced a remarkable 60% reduction in coronary heart disease mortality since the 1970s, largely due to reductions in things like smoking. However, coronary heart disease remains the leading cause of premature death.

This study wanted to find out whether the decline was mainly due to medicines, like statins, or population-wide approaches like stopping smoking, good diet and exercise. They also knew that many of the risk factors of coronary heart disease show a social gradient, with the poorest worst affected. The team were interested in whether medicines or lifestyle changes made these social inequality differences bigger or smaller.

Modelling studies like this use existing data to estimate the relative impact of different variables (e.g. statin use) on an outcome (e.g. death). The advantage of models are that you can play around with the parameters to see what the most important influences are, and this can help target resources to give the most value for money in the future. However, all models rely on a range of assumptions and are only as good as the quality of their inputs and their design.

As the old software engineer saying goes “GIGO”: garbage in, garbage out.

It’s important to assess whether the model has realistic assumptions and if its data is relevant and of good quality.

 

What did the research involve?

The study team pulled together data from randomised controlled trials, meta-analyses, national surveys and official statistics to input into a statistical model. They then ran a series of statistical tests to estimate whether the relative contribution preventative medicines, reduction in blood pressure and cholesterol levels had contributed to the decrease in coronary heart disease deaths. The data came from adults over 25 living in England, gathered between 2000 and 2007. 

The main outcome of interest was number of deaths prevented or postponed (DPPs) in 2007, stratified by socioeconomic status.

For the number crunching, they used a model called the “IMPACTSEC model”.

This is a statistical technique that takes results from previous studies to make an estimate about the relative contributions, specific treatment and risk factors make to reductions in death rates. 

Or, in laypersons’ terms: it takes results from previous studies to make an estimate about how likely a particular intervention is in preventing or postponing deaths.

The first part of the IMPACTSEC model calculates the net benefit of statins and antihypertensive treatment in 2007. The second part of the IMPACTSEC model estimates the number of DPPs related to changes in systolic blood pressure and cholesterol levels in the population. They realised that there was overlap between pharmacological and non-pharmacological contributions to risk factors, and adjusted for this in their model.

 

What were the basic results? Populations approach vs. medications

In 2007, the model estimated that there were approximately 38,000 fewer coronary heart disease deaths than if death rates had continued at 2000 levels. A large proportion of these, approximately 20,400 DPPs, were attributable to reductions in blood pressure and cholesterol in the English population (population-based approached). A much smaller number, approximately 1,800 DPPs, came from medications such as statins.

The remaining DPPs were attributed to other factors.

Impact by socioeconomic group

Reductions in population blood pressure prevented almost twice as many deaths in the most deprived fifth of society compared with the most affluent.

Reductions in cholesterol resulted in approximately 7,400 DPPs, of which 5,300 DPPs were attributable to statin use and approximately 2,100 DPPs to population-wide changes.

Statins prevented almost 50% more deaths in the most affluent fifth of society compared with the most deprived. Conversely, population-wide changes in cholesterol prevented threefold more deaths in the most deprived fifth of society compared with the most affluent.

 

How did the researchers interpret the results?

The study team welcomed the reductions in death rates from coronary heart disease over the last 30 years, but raised concerns that the improvements were not spread equally amongst society. They questioned whether health inequalities might get worse if future efforts focussed on policies to increase the use of statins, rather than on population-based approaches.

They concluded: “Our results strengthen the case for greater emphasis on preventive approaches, particularly population-based policies to reduce SBP [systolic blood pressure] and cholesterol”.

 

Conclusion

This modelling study estimated that population-based approaches to reduce heart disease death rates in England have helped the poorest in society the most, while the effect of statins has benefited the most affluent. This led the study authors to suggest that there needs to be a greater emphasis on population-based approaches in the future, if we are not to see health inequalities widen.

Report author Martin O'Flaherty said in the Telegraph that: “The success of clinical cardiology in providing cost-effective treatments that are based on scientific evidence needs to be celebrated. However, population-wide measures might offer substantially bigger health gains, relieve pressure on an already stressed health system and reduce health inequalities. Measures like controlling tobacco, increasing physical activity, improving the contents of processed food products, restricting the marketing of junk food, taxation of sugary drinks, and subsidies to make healthier foods more affordable require renewed attention not just from academics, but crucially from people and policymakers”.

It is not totally clear how reliable and robust the model used in the study was, or the conclusions that stemmed from it. It is possible that different results and conclusions could have been reached if the inputs had been from different data sources, or the model configured differently.

That said, the researchers took all reasonable measures to mitigate this, and their conclusions remained stable throughout, so we can consider it relatively reliable. The reliability of the conclusions would be increased if they were supported by other studies using a variety of data sources.

The study is useful in informing debate in the public health world about the best and fairest way of reducing heart disease deaths in England, which is always a question of targeting and prioritising finite resources. 

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Mass prescription of statins ‘will widen social inequalities’. The Independent, January 23 2015

Fall in heart deaths is due to healthy living - NOT statins, study claims. Mail Online, January 23 2015

Statins save fewer lives than exercising and eating sensibly, say scientists. The Daily Telegraph, January 23 2015

Links To Science

Guzman M, Ahmed R, Hawkins N, et al. The contribution of primary prevention medication and dietary change in coronary mortality reduction in England between 2000 and 2007: a modelling study. BMJ Open. Published online January 22 2015

Categories: NHS Choices

Angry Twitter communities linked to heart deaths

Fri, 23/01/2015 - 11:10

"Angry tweeting 'could increase your risk of heart disease','' is the poorly reported headline in The Daily Telegraph. The study it reports on found there is a link between angry tweets and levels of heart disease deaths.

Researchers were interested in investigating how various forms of negative psychological stress are linked to heart disease. They looked at how angry tweets, at a community level, may be a reflection of this stress.

For example, people living in an area with a high crime rate and high unemployment may be more likely to vent their anger on Twitter than people living in luxury flats in Mayfair.

And stress and other negative psychological emotions could increase the risk of heart disease.

The study looked at 148 million tweets across US counties and linked them to information on heart disease deaths, as well as demographic risk factors such as age and ethnicity.

Inputting this information into a mathematical model allowed the researchers to broadly predict death rates from heart disease using only the language analysis of Twitter posts, such as looking for swear words.

From a research point of view, this is exciting as it is a new avenue for gathering health insights, which in turn could ultimately help us target health resources at areas that need them most. It would be interesting to see if a UK-based study yielded similar results.

 

Where did the story come from?

The study was carried out by researchers from the University of Pennsylvania.

It was funded by The Robert Wood Johnson Foundation's Pioneer Portfolio through an Exploring Concepts of Positive Health Grant, and a grant from the Templeton Religion Trust.

The study was published in the peer-reviewed Psychological Science.

The Daily Telegraph's headline that, "Angry tweeting could increase your risk of heart disease" is not correct. The study was about how existing psychological stress is linked to heart disease, and angry tweets may be a reflection of this stress.

A more accurate (if a little lengthy) headline would be: "Stress and other negative psychological emotions increase risk of heart disease, and these people are more likely to send angry tweets".

Despite the misleading headline, the rest of the article was accurate. It ran useful quotes from experts explaining how language patterns can reflect negative emotions such as stress, and this in turn is linked to poorer health, particularly heart health.

"Psychological states have long been thought to have an effect on coronary heart disease. For example, hostility and depression have been linked with heart disease at the individual level through biological effects […].

"But negative emotions can also trigger behavioural and social responses; you are also more likely to drink, eat poorly and be isolated from other people, which can indirectly lead to heart disease."

 

What kind of research was this?

This was a cross-sectional study looking at whether the language used on Twitter across a range of US counties was a good predictor of underlying psychological characteristics and death rates from heart disease.

Heart disease is the leading cause of death worldwide. Identifying and addressing key risk factors for heart disease, such as smoking, hypertension, obesity and physical inactivity, has significantly reduced this risk, the researchers state.

Psychological characteristics, such as depression and chronic stress, have also been shown to increase risk through physiological effects.

Like individuals, communities have characteristics, such as cultural norms (beliefs about how members of a community should behave), social connectedness, perceived safety and environmental stress, that contribute to health and disease.

One challenge of addressing community-level psychological characteristics is the difficulty of assessment. Traditional approaches using phone surveys and household visits are costly and have limited precision.

The study team thought Twitter might provide a more cost-effective assessment of community-level psychology, which is linked to death and disease.

Previous studies based on user-generated content, such as using Google searches to predict the likely spread of flu, have proved successful.

 

What did the research involve?

The researchers gathered 148 million tweets geographically linked to 1,347 counties in the US. It was reported more than 88% of the US population lives in the counties included.

The team then gathered country-level information on heart disease (coronary heart disease) and death, as well as a range of demographic and health risk factor information, such as average income and proportion of married residents.

In 2009 and 2010, Twitter made a 10% random sample of tweets (a data-mining initiative titled the "Garden Hose") available for researchers through direct access to its servers. This was how the researchers accessed the tweets.

The language analysis automatically calculated how often words and phrases were used on Twitter for each county, such as "hate" or "jealous", and categorised them according to theme.

They also searched for swear words we couldn't possibly repeat to a PG audience. Themes included anger, anxiety, positive and negative emotions, engagement, and disengagement.

Because words can have multiple senses, act as multiple parts of speech, and be used ironically, the researchers manually checked a sample of the automatically generated themes to ensure they were accurate.

All the information was fed into a statistical model to see if it was possible to predict heart disease death rates from the language used on Twitter alone.

 

What were the basic results?

Greater use of anger, negative relationship, negative emotion, and disengagement words on Twitter was significantly correlated with greater age-adjusted heart disease mortality. Protective factors included positive emotions and psychological engagement.

Most correlations remained significant after controlling for income and education.

The statistical model – based only on Twitter language – predicted heart disease deaths significantly better than a model that combined 10 common demographic, socioeconomic, and health risk factors, including smoking, diabetes, hypertension, and obesity.

 

How did the researchers interpret the results?

The researchers reached a simple conclusion: "Capturing community psychological characteristics through social media is feasible, and these characteristics are strong markers of cardiovascular mortality at the community level."

 

Conclusion

This study shows it is possible to broadly predict death rates from heart disease at a US county level using language analysis of Twitter posts from those US counties.

From a research point of view, this study is exciting as it gives an extra way of gathering information that could ultimately help target health resources in areas that need it most.

The cost effectiveness of this type of psychological insight would be interesting to weigh against existing methods such as telephone interviews.

But this was just a single study, so we cannot be sure this technology is practical or useful in a wide range of applications. This would depend on how speech is related to other health risk factors.

Nonetheless, this is an interesting avenue for further investigation. The research community is always looking for new cost-effective methods of gathering data to improve people's health.

This study suggests language analysis of Twitter, in some circumstances, might be a useful activity. This could potentially be used to assess a wide range of issues, such as depression rates, the prevalence of eating disorders, and levels of alcohol or drug misuse in a given community.

It will be interesting to see where this avenue of research, based on user-generated content, takes us.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Angry tweeting 'could increase your risk of heart disease'. The Daily Telegraph, January 22 2015

Links To Science

Eichstaedt JC, Schwartz HA, Kern ML, et al. Psychological Language on Twitter Predicts County-Level Heart Disease Mortality. Psychological Science. Published online January 20 2015

Categories: NHS Choices

New heart attack test shows promise for women

Thu, 22/01/2015 - 12:00

"Doctors could spot twice as many heart attacks in women by using a newer, more sensitive blood test," BBC News reports.

In women, for reasons that are unclear, a heart attack often doesn't trigger the symptom most people associate with the condition: severe chest pain, memorably described as like having an elephant sitting on your chest. This can lead to delays in diagnosis, which may impact on clinical outcomes.

A more sensitive blood test has been developed that can help determine if a person with the symptoms of a heart attack has actually had one.

The new test is more sensitive to levels of a protein called troponin, which is released into the bloodstream when there is damage to heart muscle.

The test was used on more than 1,000 people investigated for a suspected heart attack, in addition to the standard diagnostic protocols, such as an electrocardiogram (ECG).

The researchers found if the new test was used alongside standard protocols, the rate of accurate heart attack diagnoses in women would have doubled. The test had less impact on the diagnosis for men.

If the larger studies now underway confirm these results, more women may be identified who have had a heart attack and are therefore in need of preventative strategies, which, as the BBC rightly concluded, could save thousands of lives.

 

Where did the story come from?

The study was carried out by researchers from the University of Edinburgh, the Royal Infirmary of Edinburgh, Southern General Hospital, St George's Hospital and Medical School, and the University of Minnesota.

It was funded by the British Heart Foundation with support from the legacy of Violet Kemlo. The tests were provided by the US pharmaceutical company Abbott Laboratories, but it is reported they had no role in the study design or analysis.

The study was published in the peer-reviewed British Medical Journal (BMJ) on an open-access basis, so it is free to read online.

The UK media covered the story accurately, and BBC News also provided expert opinion from Professor Peter Weissberg of the British Heart Foundation (BHF).

He reported the BHF are now funding a larger study to confirm the results, and from this it is hoped more women will be identified who could benefit from preventative measures.

However, the media did not discuss the important finding that even after a diagnosis of heart attack has been made, women were not referred for further investigations or treatment as often as men.

This could suggest potential gender inequality in terms of diagnostic and treatment protocols that may need to be investigated further.

 

What kind of research was this?

This was a cohort study that aimed to see if a more sensitive blood test could improve the diagnosis of a heart attack and help predict who is at risk of having a further heart attack.

The blood test was used in addition to standard investigations for people who presented to hospital with a suspected heart attack.

The results of the test were not given to the doctors, so did not influence their decisions on treatment, prevention or management.

The researchers recorded which people went on to have a heart attack or die in the next 12 months to see if the new blood test was more accurate.

When there is damage to heart muscle, the cells that die release a protein called troponin into the bloodstream. Higher levels of troponin indicate greater damage.

Troponin levels are routinely checked when someone has symptoms of acute coronary syndrome, a medical emergency where the supply of blood suddenly becomes restricted, resulting in damage to the heart.

Acute coronary syndrome includes:

  • myocardial infarction (heart attack)
  • unstable angina (symptoms and ECG changes, but no increase in troponin levels)
  • non-ST-elevation myocardial infarction – a "milder" type of heart attack (though still extremely serious) where there is a partial blockage of the blood supply to the heart (symptoms and increased troponin levels, but no ECG changes)

People with acute coronary syndrome are at risk of having a heart attack or another heart attack, depending on the diagnosis. For example, if unstable angina is left undiagnosed and untreated, the condition can escalate into a heart attack.

 

What did the research involve?

All adults presenting to Edinburgh Royal Infirmary with suspected acute coronary syndrome were enrolled in the study between August 1 and October 31 2012.

Troponin levels were measured using the standard test as well as the new, more sensitive test. The tests were performed on admission and again six to 12 hours later.

The doctors were not given the results of the new test, so they based their diagnosis and management on the standard troponin test, symptoms, ECG results and other imaging.

The researchers looked at the clinical records from admission to 30 days. They analysed whether the level of troponin in the new test could predict outcomes such as a heart attack or death.

They used a single cut-off level of troponin 26ng/L, and then a higher level for men of 34ng/L and a lower threshold of 16ng/L for women.

They then calculated whether these levels could predict outcomes at 12 months, and adjusted the results to take into account age, kidney function and other medical conditions.

 

What were the basic results?

In total, 1,126 people attended the hospital with suspected acute coronary syndrome (mean age 66, 55% men).

Test results

A heart attack was diagnosed in:

  • 55 women (11%)
  • 117 men (19%)

If the new troponin test had been used with the sex-specific cut-offs, twice as many women would have been diagnosed with a heart attack:

  • 111 women (22%)
  • 131 men (21%)

These additional women had a similar risk of having a heart attack or dying within the next 12 months as women who were diagnosed.

After adjusting the results to take account of age, renal function and diabetes, compared with people with no ECG changes and negative troponin tests, the likelihood of having a heart attack or dying within the next 12 months was:

  • six times more likely in women diagnosed with the new test and ECG changes (odds ratio [OR] 6.0, 95% confidence interval [CI] 2.5 to 14.4)
  • nearly six times more likely in women diagnosed with the standard test and ECG changes (OR 5.8, 95% CI 2.3 to 14.2)
  • just over five times more likely in men diagnosed with the new test and ECG changes (OR 1.5 to 19.9)
  • three times more likely in men diagnosed with the standard test and ECG changes (OR 1.1 to 3.8)

The new test would not have missed anyone currently diagnosed with a heart attack.

Management

Women with a diagnosis of heart attack using the standard tests were less likely than men to:

  • be referred to a cardiologist (80% women versus 95% men)
  • be given statin treatment (60% versus 85%)
  • have coronary angiography – imaging of the heart (47% versus 74%)
  • have coronary angioplasty – a surgical intervention to reopen the vessels of the heart (29% versus 64%)

Women who would have been diagnosed with a heart attack using the new test and the ECG changes were the least likely to have any further investigations.

 

How did the researchers interpret the results?

The researchers concluded that, "Although having little effect in men, a high-sensitivity troponin assay with sex-specific diagnostic thresholds may double the diagnosis of myocardial infarction in women, and identify those at high risk of reinfarction [further heart attack] and death."

They go on to say that, "Whether use of sex-specific diagnostic thresholds will improve outcomes and tackle inequalities in the treatment of women with suspected acute coronary syndrome requires urgent attention."

 

Conclusion

This new study showed how a more sensitive test of troponin levels would have led to a diagnosis of heart attack in double the number of women studied.

The test made less of a difference to the diagnosis for men. This could be because the troponin levels in the standard test were much higher in men than women.

The research also indicates that even with a diagnosis of heart attack, women were less likely to be referred to cardiologists or have any further investigations or treatment, such as a coronary angiography or coronary angioplasty.

The researchers found women who would have been diagnosed with a heart attack with the new test were even less likely to be referred, prescribed a statin, or have vessel surgery, despite having ECG changes.

In both cases, the reasons for this are unclear. It is also not known what other preventative strategies were actually implemented, such as:

  • thinning the blood with aspirin
  • treating high blood pressure
  • optimising the treatment of any comorbid conditions, such as diabetes
  • supporting lifestyle changes, including stopping smoking, reducing obesity and inactivity

The reasons for this are not clear. So it is also unclear what difference an increase in diagnosis would make to outcomes if these underlying gender inequalities in heart attack management are not also addressed. Arguably, this issue warrants further investigation.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Newer heart attack test 'could save women's lives'. BBC News, January 21 2015

New test could detect twice as many heart attacks in women. The Daily Telegraph, January 21 2015

£20 heart attack test will save thousands of women: Doctors believe new check will double chance of identifying damaged cells. Mail Online, January 21 2015

Links To Science

Shah ASV, Griffiths M, Lee KK, et al. High sensitivity cardiac troponin and the under-diagnosis of myocardial infarction in women: prospective cohort study. BMJ. Published online January 21 2015

Categories: NHS Choices

Claims that 'men worsen labour pains' are unproven

Thu, 22/01/2015 - 11:00

"It’s official: men really shouldn’t be at the birth,” is the bizarre headline in The Times, as it reports on a pain study on women who were not even pregnant, let alone giving birth.

Researchers wanted to explore whether a woman’s “attachment style” (whether they sought or avoided emotional intimacy) had any influence on whether it was beneficial to have their partners present while having painful medical procedures.

They administered a series of painful laser pulses to 39 female volunteers in both the presence and absence of their romantic partners, while recording the women’s pain ratings.

The study found that the more women reported wanting to avoid closeness and intimacy, the more pain they experienced when their romantic partner was present.

However, describing the partner as “present” is misleading. The partner was in the same room, but hidden behind a curtain, so they could not see each other or have basic physical contact, such as holding hands. They were also told not to communicate. This does not mimic real-life situations, where a partner might be able to offer support. Therefore, media attempts to extrapolate these findings to childbirth are misguided.

The study makes the interesting point that health professionals should not assume a romantic partner is the best choice to accompany a patient undergoing a painful medical procedure. A relative or friend may be a better option.

 

Where did the story come from?

The study was carried out by researchers from King’s College London, the University of Hertfordshire and University College London. It was funded by the Volkswagen Foundation, the European Research Council and the Economic and Social Research Council.

The study was published in the peer-reviewed journal Social, Cognitive and Affective Neuroscience on an open-access basis, so it is free to read online or download as a PDF.

The Times’ reporting of this study was poor. Its headline of “It’s official: men really shouldn’t be at the birth” fails to communicate the fact that this study did not actually involve pregnant women.

The term “It’s official” is also deeply unhelpful. It implies that there is some official guideline dictating who should be a woman’s birth partner. Even if there were such a guideline, a small study involving 39 non-pregnant women wouldn’t be a reason to change it.

Other UK media sources ran similar reports to The Times, with the honourable exception being BBC News, which reported the study accurately, though they did not explain that the partner was silent and behind a curtain.

 

What kind of research was this?

This study was a comparative case series. It looked at whether the degree of pain women experience during medical procedures is affected by the presence or absence of their romantic partner. It also looked at whether this is influenced by the woman’s “attachment style” in terms of whether they sought or avoided emotional intimacy in their relationships.

Previous research on the subject has been mixed, with some studies indicating that the presence of someone close is beneficial in reducing pain, and others suggesting that the opposite is true. The researchers decided to look at how personality factors, specifically “adult attachment style”, might influence the effects of the presence of someone close, when a woman is experiencing pain.

 

What did the research involve?

The researchers recruited 39 heterosexual couples in a romantic relationship, using university circular emails. The female participants had to fulfil the specific criteria to be included. They had to:

  • be right-handed
  • have been in their current relationship at least a year
  • have no history of mental illness
  • have no history of medical or neurological conditions
  • have no history of substance abuse
  • had not taken any medication, including painkillers, on the day of testing

The average age of participants was about 25 for women and 27 for men, and they were predominantly white British. They were paid £30 per couple for participating.

The couples all underwent three experiments, in which the woman was given moderately painful laser pulses on one of their fingers, lasting for around 10 minutes. They were told that the experiments were aimed to test empathy in the partner, rather than the actual intention of rating the level of pain experienced by the woman. These experiments were performed in different orders across the couples.

In one experiment, the male partner was asked to rate his empathy for his partner while she was receiving the painful stimuli. Each partner was given visual information on the intensity of the laser, but they could not see each other as they were divided by a curtain.

In the second experiment, the partner was asked to rate his empathy for another participant who had previously taken part in the experiment, by viewing information on the laser intensities they had received, while their own partner received laser stimuli. In this experiment, the male partner was therefore unable to pay attention to his own partner and they were still separated by a curtain.

In the third experiment, the researchers led couples to believe that due to a technical fault, the file for the previous participant would not load onto the lab computer. The partner was therefore going to rate his empathy on a computer next door, and would be absent from the testing room.

Couples were instructed not to communicate during the procedures, to avoid biasing participants’ pain ratings.

In each experiment, the women were asked to rate the intensity of the pain on an 11-point scale, ranging from 0 (no pinprick sensation) to 10 (the worst pinprick sensation imaginable). The level of laser stimulation was set individually for each woman before the experiments, during “familiarisation with the equipment” so that it delivered a pain rating of 8. During each experiment, the women entered their ratings on a computer screen, using a numeric keypad. 

The researchers also positioned 11 electrodes on each woman’s scalp to measure the brain’s electrical activity while she was having the laser stimulation. Using the EEG recording, researchers measured whether this electrical activity “spiked” in response to the laser pulses.

Each woman also completed a validated 36-item questionnaire on close relationships, to measure the extent to which she either sought closeness or emotional intimacy in relationships. The questionnaire included 18 questions about “attachment style”.

 

What were the basic results?

The study found that the more women reported wanting to avoid closeness, the more pain they experienced when their romantic partner was present, and the stronger their “peaks” in brain activity.

Whether the partner was focusing on them or on another woman’s pain made no difference to the pain experienced.

 

How did the researchers interpret the results?

The researchers say that the effects of a partner’s presence on women’s pain ratings depended on their “attachment style” and that a partner’s presence may not have beneficial effects on the experience of pain when the individual in pain has “higher attachment avoidance”.

Partner support during painful procedures may need to be tailored to individual personality traits, they conclude. Senior author Dr Katerina Fotopoulou, from UCL Psychology & Language Sciences, says: “Individuals who avoid closeness may find that the presence of others disrupts their preferred method of coping with threats on their own. This may actually maintain the threat value of pain and ultimately heighten individual’s pain experience.”

 

Conclusion

This small study found that during painful stimuli, how much pain women reported experiencing depended on their attachment style – with more pain being experienced by women who have a "higher attachment avoidance", when their romantic partner was present.

The study was interesting, but had several limitations. The major one was that it did not allow the partners to communicate, have visual contact or basic physical contact, such as holding their hand during the painful procedures. This does not reflect the support that would be expected from a partner in a real life situation and may have influenced the results. In addition, the study's findings may not be generalisable to older couples or those from ethnic minorities.

Neither is it certain if these results would apply to real life painful procedures or experiences –including childbirth. As Dr Fotopoulou points out: “The physical and psychological nature of labour pain may simply be different than other types of pain. Future studies could test how having a partner present during labour affects the pain felt by women who tend to avoid closeness in relationships.”

It makes sense that some women – or people in general – may feel they can cope with pain better when alone than with a partner. Deciding who should be present during labour is entirely personal, although many women find the support of someone close, whether it is a partner, friend or relative, comforting.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

It’s official: men really shouldn’t be at the birth. The Times, January 21 2015

Fathers in delivery room could make pain of childbirth worse, study suggests. The Daily Telegraph, January 21 2015

Partners can worsen childbirth pains for the intimacy-averse, study finds. The Guardian, January 21 2015

Childbirth pain could be made WORSE by presence of partner, says study. Daily Mirror, January 21 2015

Women patients feel more pain when with partner, study suggests. BBC News, January 21 2015

Links To Science

Krahé C, Paloyelis Y, Condon H, et al. Attachment style moderates partner presence effects on pain: a laser-evoked potentials study. Social Cognitive and Affective Neuroscience. Published online January 1 2015

Categories: NHS Choices

Nordic IVF outcomes improving - is the same true for the UK?

Wed, 21/01/2015 - 12:00

"The health of artificially conceived children has steadily improved in the last 20 years," The Guardian reports. Researchers who analysed data from Nordic countries described the decline in premature and stillbirths as "remarkable".

This was the main finding of a large cohort study comparing the health of babies born using assisted reproduction technology (ART), such as in vitro fertilisation (IVF), with those conceived naturally over the last 20 years.

They found big improvements over time in a number of areas, including reductions in the number of miscarriages and babies born prematurely or with a low birth weight. All of these can be complications of multiple births (twins, triplets, or sometimes more).

The study looked at ART in Norway, Sweden, Denmark and Finland, and it is unclear whether we could expect to see similar improvements in the UK.

While it is likely we share similar advances in technology and improved protocols with Nordic countries, there may be other important differences as a result of eligibility for treatment.

In some Nordic countries, eligibility for reproductive treatment has been extended to include couples with less severe fertility problems. This may have accounted for some of the improvements seen over the years.

The most recent UK data from 2013 (PDF, 2.54Mb) reports the ART multiple birth rate has fallen from 25% in 2008 to 16% in 2013. This would suggest a potentially similar improvement in UK outcomes for ART.

 

Where did the story come from?

The study was carried out by researchers from universities based in Denmark, Norway, Sweden and Finland.

It was funded by the European Society of Human Reproduction and Embryology, the University of Copenhagen, the Nordic Federation of Societies of Obstetrics and Gynecology, and the Danish Agency for Science, Technology and Innovation.
 
The study was published in the peer-reviewed medical journal Human Reproduction. The article was published on an open-access basis, meaning anyone can view it and download it for free.

Generally, The Guardian and the Mail Online reported the study accurately, though neither made it clear in their headlines this was actually research involving Nordic countries and not the UK.

 

What kind of research was this?

This was a population-based cohort study looking at the health outcomes of babies born through assisted reproductive technology over the last 20 years.

Assisted reproductive technology (ART) is a catch-all term for a number of techniques that can help parents to conceive and have a baby. Two of the most common are IVF and intra-cytoplasmic sperm injection (ICSI).

In IVF, a woman's eggs are removed from her ovaries by a doctor and cultured with many sperm in a laboratory. This allows fertilisation to take place "naturally", but outside the body.

If embryos develop, one, or sometimes two or three (depending on circumstances), are transferred to the woman's uterus to grow and develop into a baby.

Intra-cytoplasmic sperm injection (ICSI) differs from IVF in that a specialist selects a single sperm to be injected directly into an egg, instead of fertilisation taking place in a dish, where many sperm are placed near an egg.  

The study also included people who have had frozen embryo transfer. After IVF, a couple may have a number of unused (non-transferred) embryos. They can freeze them for use in later treatment cycles or for other purposes, such as donation.

 

What did the research involve?

The researchers analysed the health outcomes shortly after birth of 62,379 single babies and 29,758 twins born by ART between 1988 and 2007 in Sweden, Norway, Denmark and Finland.

They compared babies born through ART (IVF, ICSI or frozen embryo transfer) with a control group of 362,215 babies conceived naturally.

Twins conceived after ART were compared with all naturally conceived twins (n=122, 763) born in the Nordic countries during the study period.

The rates of several adverse health outcomes were stratified into the time periods 1988-92, 1993-97, 1998-2002 and 2003-07 to assess possible changes over time.

Babies born though ART were matched to naturally conceived babies according to parity (whether they were born as a single baby, twins, triplets or higher multiples) and year of birth.

Adverse outcomes they were looking at included:

  • low birth weight – defined as birth weight less than 2,500g
  • very low birth weight – less than 1,500g
  • preterm birth – defined as birth before 37 weeks of development
  • very preterm birth – birth before 32 weeks of development
  • small for gestational age – less than two standard deviations
  • large for gestational age – more than two standard deviations calculated using Marsal's formula
  • stillbirth – defined in this study as death of the infant after more than 28 weeks of development (in the UK it is above 24 weeks)
  • infant death – death of the infant in the first year of life

Statistical analysis adjusted for parity, year of birth, and country of birth.

 

What were the basic results?

For singletons conceived after ART, a decline in the risk of being born preterm and very preterm was observed.

The proportion of ART singletons born with a low and very low birth weight also decreased.

The stillbirth and infant death rates declined among both ART singletons and twins.

Throughout the 20-year period, fewer ART twins were stillborn or died during the first year of life compared with spontaneously conceived twins.

The researchers thought this was "presumably due to the lower proportion of monozygotic [identical] twins among the ART twins".

 

How did the researchers interpret the results?

Discussing the wider implications of their findings, the team says that, "It is assuring that data from four countries confirm an overall improvement over time in the perinatal [around the time of birth] outcomes of children conceived after ART.

"Furthermore, data show the beneficial effect of single embryo transfer, not only in regard to lowering the rate of multiples, but also concerning the health of singletons."

 

Conclusion

This study found an improvement in health outcomes around the time of birth for babies conceived using artificial reproductive technology (IVF, ICSI and frozen embryo transfer) over the last 20 years in four Nordic countries (Norway, Sweden, Denmark and Finland). 

The study sample was large and the methods robust. This means we can be relatively confident these results paint an accurate picture of what is going on in these countries.

But two questions remain: are similar results found in the UK, and what is behind the improvement?

On the first question, it is difficult to say without having direct UK data. The Nordic countries are famous for having highly developed and supportive healthcare systems, which may include differences in specific ART techniques and follow-up care.

Each country is also likely to have different eligibility criteria that must be met to receive ART. These differences could influence whether improvements in ART would be seen across other countries.

The bottom line is we can't be sure the same situation is happening in the UK based on this study. We need solid information from the UK system itself.

There are a number of possible explanations for what caused the improvements. The most important reason, the research team said, was the dramatic decline in multiple births due to elective single embryo transfer.

In IVF, there is the option of implanting a single embryo into the mother, or more than one. During the study, the rate of twin births was reduced by one-third. Twin births are much more likely when implanting more than one embryo. Some research has associated double embryo transfer with an increased risk of preterm birth and perinatal mortality in ART children.

The improvements may also reflect a change in the people who were undergoing ART. The study authors, for example, say previously only couples with severe fertility problems would be eligible to undergo ART treatment, whereas in recent years this has been extended to allow less severe cases.

ART may be less likely to be successful and may result in poorer birth outcomes in more severe cases (depending on the nature of the problem).

Refinement of clinical and laboratory skills also may have had a positive impact on the outcomes of the children.

But there has been a similar decline in multiple births through ART in the UK, dropping from one in four in 2008 to around one in six in 2012. This would suggest the quality of ART services in the UK are moving in the right direction.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

IVF babies see health improvement with fewer underweight or stillborn. The Guardian, January 21 2015

IVF babies are less likely to be born prematurely or die in infancy than 20 years ago, study reveals. Mail Online, January 21 2015

Links To Science

Henningsen AA, Gissler M, Skjaerven R, et al. Trends in perinatal health after assisted reproduction: a Nordic study from the CoNARTaS group. Human Reproduction. Published online January 20 2015

Categories: NHS Choices

'Social jet lag' linked to obesity and 'unhealthy' metabolism

Wed, 21/01/2015 - 11:30

"Social jet lag is driving obesity" is the misleading headline in The Daily Telegraph. A new study only found a link between "social jet leg", obesity, and metabolic markers that may indicate a person has an increased risk of obesity-related diseases, such as type 2 diabetes. A cause and effect relationship was not found.

Social jet lag is the term used to describe the difference in someone's sleep patterns between work days and free days – also known as having a lie-in at the weekend.

The researchers' hypothesis was that regularly disrupting our sleep patterns could upset the body clock (circadian rhythms), which could then have a harmful effect on the metabolism.

The study of more than 800 non-shift workers found people with a greater difference in sleep patterns between free days and work days were more likely to be obese and "metabolically unhealthy" (have markers for obesity-related diseases) than those with little or no difference between these timings.

But the study does not prove regular lie-ins cause obesity or obesity-related diseases, as it assessed sleep patterns and health at the same time. It is possible with this type of study that the reverse is true – that obesity and any associated health conditions may cause people to lie in more.

Overall, this study provides no proof having a lie-in will affect your health, though the occasional early-morning Saturday stroll may improve both your fitness and wellbeing.

 

Where did the story come from?

The study was carried out by researchers from the Medical Research Council (MRC) and the University of London in the UK, Duke University and the University of North Carolina in the US, and the University of Otago, New Zealand.

It was funded by the US National Institute of Aging and the MRC.

The study was published in the peer-reviewed International Journal of Obesity.

The quality of the UK's media coverage of the study was mixed. The Independent correctly mentioned there was no proof social jet lag causes obesity, but none of the papers mentioned the possibility of reverse causation: that obesity makes people more likely to lie in, rather than lie-ins causing obesity.

The Daily Telegraph's choice of headline was particularly unhelpful, as it implied social jet lag was now a proven partial cause of the obesity epidemic and the related complications. This is not the case.

 

What kind of research was this?

This was a cross-sectional analysis of a cohort study that aimed to look at the association between obesity and metabolic markers that may indicate obesity-related disease, and social jet lag. Social jet lag is a measure of the discrepancy in sleep timing between our work and free days.

The researchers say travel-induced jet lag results in problems with circadian rhythms (the body's internal clock), which causes temporary problems with metabolic rate (the rate at which the body uses up energy).

However, they suggest social jet lag can become chronic throughout someone's life and therefore have longer term consequences for metabolism, possibly increasing the risk of metabolic syndrome. Metabolic syndrome is the medical term for a combination of diabetes, high blood pressure and obesity.

The researchers also say recent research found people with higher social jet lag and a greater discrepancy between internal and social clocks were found to have a higher self-reported body mass index (BMI).

They consider it possible that if our internal clocks are at odds with external schedules, this may partly underlie the increase in obesity seen in the last few decades.

Cross-sectional studies look at all data at the same time, so they cannot be used to see if one factor (in this case, social jet lag) has caused the others (in this case, obesity or metabolic markers).

 

What did the research involve?

This study included 815 non-shift workers who were participants of an ongoing health study in New Zealand (Dunedin Longitudinal Study), which is following more than 1,000 people born between 1972 and 1973 to investigate links between health and behaviour.

At the age of 38, each participant was asked to fill in a standard questionnaire to assess social jet lag, as well as sleep duration and chronotype (their "natural" preference in sleep timing). 

Social jet lag was measured by subtracting each person's midpoint of sleep on work days from their midpoint of sleep on free days (assuming five work days and two free days a week as standard).

So, for example, if someone slept from 12am to 8am on workdays, the midpoint was 4am. If they then slept from 1am to 11am on free days, the midpoint was 6am, giving a social jet lag of two hours.

Researchers also measured participants' height and weight to calculate BMI, with obesity defined as a BMI of 30 or more. Waist circumference and fat mass were also measured.

The researchers also assessed whether participants had markers of metabolic syndrome, a disorder associated with diabetes and obesity.

They assessed five biomarkers, and people with "high-risk values on three or more" were defined as having metabolic syndrome. These were:

  • waist circumference (88cm or more for women, 102cm or more for men)
  • high blood pressure (130/85mm Hg or higher)
  • low levels of high-density lipoprotein (HDL, or "good") cholesterol
  • high triglycerides (another blood fat)
  • high blood levels of a glycated haemoglobin (an indicator of blood glucose control –  a marker for diabetes)

They also assessed blood levels of an inflammatory marker called C-reactive protein.

The authors say recent research has shown a subset of obese individuals who are "metabolically healthy". They therefore created a measure for obesity status with three levels:

  • non-obese (a BMI of below 30)
  • healthy obese (a BMI of 30 or above, but no metabolic syndrome)
  • unhealthy obese (a BMI of 30 or above and metabolic syndrome)

Researchers also asked people about their current smoking status (since smoking is positively associated with jet lag and may also keep weight low) and socioeconomic status, assessed by their current or most recent occupation.

They were then allocated to one of six categories (from 1 – unskilled labourer to 6 – professional). Those not working were rated according to their educational status.

Researchers analysed their results to determine if social jet lag was associated with "unhealthy" obesity. They created three models, with one adjusting the figures for potential confounders, including smoking, socioeconomic status, sleep duration, and sleep preferences.

 

What were the basic results?

The researchers report social jet lag was associated with numerous measures of metabolic dysfunction and obesity, with higher social jet lag levels in "metabolically unhealthy" obese individuals.

Among metabolically unhealthy obese individuals, social jet lag was additionally associated with high blood levels of glycated haemoglobin and CRP (an indicator of inflammation).

Individuals with higher social jet lag scores were more likely to be obese (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.0 to 1.5) and to meet the researchers' criteria for metabolic syndrome (OR 1.3, 95% CI 1.0 to 1.6) – though both of these risk increases are only of borderline statistical significance.

 

How did the researchers interpret the results?

The researchers say the findings are consistent with the possibility that, "living against our internal clock may contribute to metabolic dysfunction and its consequences".

They suggest a two-hour difference in sleep patterns at the weekend is the "threshold" for a higher BMI and other biomarkers, although they also point out this association was weakened or non-significant once smoking and socioeconomic status were taken into account.

Further research is needed, they say, to determine the physiological mechanisms underlying these associations.

 

Conclusion

The study involved 815 non-shift workers. It found people with a greater difference in sleep patterns between free days and work days (so-called "social jet lag") were more likely to be obese and "metabolically unhealthy" (have markers for obesity-related diseases) than those with little or no difference between these timings.

This study adds to previous research in both animals and humans that has explored the possible effects altering the body clock may have upon our metabolism, being overweight or obese. A recent UK survey found a link between shift work and chronic diseases, which we discussed at the end of 2014.

However, this new study cannot prove regular lie-ins cause obesity or obesity-related diseases.

The study is cross-sectional, assessing sleep patterns and health at the same time. It is possible with this type of study that the reverse is true – that obesity and any associated health conditions may cause people to lie in more whenever possible.

There may be many underlying factors this study has not taken into account that are influencing the apparent relationship between obesity, metabolic markers, and higher levels of social jet lag.

For example, the study did not take account of people's diets or their exercise levels, which are two key factors that influence BMI and may also influence our sleep patterns.

The increased risks of obesity and metabolic syndrome with social jet lag were only of borderline statistical significance in any case, which further indicates the overall lack of strength in these associations.

Experts tend to agree it is best to keep to a regular sleep schedule on week days and weekends to prevent sleep problems. Whether following this advice can also keep the weight off is uncertain. Overall, this study provides no proof having a lie-in will affect your health.

Still, we can't help but agree with the recommendations of one of the authors of the study, as quoted on the Mail Online website: "I don't want to tell people not to have a lie-in because I enjoy one myself," lead study author Michael Parsons said. He then went on to recommend that employers could offer flexible hours, so staff could synchronise their week days with their weekends.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Social jet lag is driving obesity and illness, say scientists. The Daily Telegraph, January 20 2015

Fancy a lie-in on weekends? New study finds it could lead obesity and diabetes. The Independent, January 20 2015

Looking forward to your Saturday lie-in? Careful, it may be a health hazard: Changes in sleep pattern between work days and weekend can raise chance of obesity and diabetes. Daily Mail, January 21 2015

Links To Science

Parsons MJ, Moffitt TE, Gregory AM, et al. Social jetlag, obesity and metabolic disorder: investigation in a cohort study. International Journal of Obesity. Published online December 22 2014

Categories: NHS Choices

Becoming healthier may motivate your partner to join in

Tue, 20/01/2015 - 12:30

“Fitness 'rubs off on your partner’,'' BBC News reports.

This headline is based on a study of more than 3,000 married couples aged 50 and over in the UK, where at least one of the partners smoked, was inactive, or was overweight or obese at the start of the study. It followed them up and looked at their and their partner’s behaviours over time.

It found that a person was more likely to change their unhealthy behaviours if their partner did too, more so than if they had a partner who was always healthy, or one who remained unhealthy.

These behaviours included quitting smoking if they smoked, increasing physical activity levels and losing some weight.

There are some limitations to the study. For example, while the researchers took into account some factors that could affect the results, others – such as unmeasured health conditions – could still be having an impact.

Still, the findings seem plausible; working together as a team to improve health, whether it be just you or your partner, or in a larger exercise or weight loss group, may help in practical ways (such as eating the same foods), as well as boosting motivation and confidence levels.

 

Where did the story come from?

The study was carried out by researchers from University College London. Funding was provided by the US National Institute on Aging and a consortium of UK government departments co-ordinated by the Office for National Statistics. Additional support for the authors was provided by the British Heart Foundation and Cancer Research UK.

The study was published in the peer-reviewed medical journal JAMA Internal Medicine.

The coverage of this study in the news has been generally reasonable. The BBC’s headline “Fitness ‘rubs off on your partner’” may make it sound like you don’t have to do anything to get fitter – as long as your partner is – but unfortunately this is not the case.

 

What kind of research was this?

This was an analysis of data from an ongoing cohort study of older adults called the English Longitudinal Study of Ageing (ELSA). It aimed to look at the effect of a partner’s behaviour on a person making healthy behaviour changes.

If a person has unhealthy behaviours (such as eating unhealthily), their partner is also likely to, and if one of them changes this behaviour then the other often does too.

In this study the researchers specifically wanted to look at whether there was a difference in the effect of having a partner who is consistently healthy (e.g. had always eaten healthily) and one who had unhealthy behaviour but then makes a positive change (e.g. starts eating healthily).

While other studies have assessed the impact of partners changing behaviour, few have assessed this specific question.

This type of study is the best way of looking at the impact of behaviour that people choose themselves in real life. The main limitation to this type of study is that factors other than the one the researchers are looking at (called confounders) could also have an effect. The researchers can take steps in their analyses to reduce the effect of potential confounders, but they can never be entirely sure they have accounted for every confounder.

 

What did the research involve?

The ELSA study started prospectively collecting data on adults aged 50 and over in England in 1998.

For the current study researchers looked at information on 3,722 married couples who lived together, where at least one had an unhealthy behaviour or characteristic at the start of the study (smoking, physically inactive, or overweight or obese). They then looked at whether their partner’s behaviour over time had an influence on whether the person changed their unhealthy behaviours.

Participants in ELSA had taken part in the Health Survey for England in 1998, 1999 and 2001. All household members aged 50 and over, as well as partners were invited for interview. Those who enrolled were sent a computer-assisted interview and self-administered questionnaires every two years from 2002. Smoking and physical activity were assessed in every questionnaire. Every four years this assessment included a health assessment, where a nurse visited the participants in their homes. This assessment included measuring height and weight.

For the current study, the researchers analysed data for the first two consecutive assessments that the person and their partner completed. They looked at smoking, physical activity and weight in people and their partners, and whether individuals:

  • quit smoking (said they smoked at the first assessment but not at the second assessment)
  • became active after being inactive (said they took part in moderate to vigorous activity less than once a week at the first assessment, but took part more often than this at the second assessment)
  • lost weight (were overweight or obese at the first assessment and had lost at least 5% of their body weight by the second assessment)

A partner was considered “consistently” healthy if they did not have the unhealthy behaviour at either the first or the second assessment.

Couples where the partner moved from a healthy behaviour to a less healthy behaviour were excluded from the analyses, as there were so few of them.

The researchers took into account a number of potential confounders in their analyses, including:

  • age
  • gender
  • socioeconomic status (household non-pension wealth)
  • health conditions (cancer, diabetes, heart disease, stroke, heart attack, or other long-standing illness that limited their activities)
What were the basic results?

At the start of the study:

  • 13.9% of men and 14.8% of women smoked
  • 31.2% of men and 35.5% of women were physically inactive
  • 77.3% of men and 67.6% of women were overweight or obese

By the next assessment overall:

  • 17% of smokers had quit
  • 44% of inactive individuals had become active
  • 15% of overweight or obese individuals had lost at least 5% of their body weight

The researchers found that when one partner changed to a healthier behaviour, the other person was more likely to also change to a healthier behaviour than if their partner had remained unhealthy. This was the case across all three behaviours:

  • If their partner stopped smoking 50% of women and 48% of men stopped smoking also, compared to only 8% stopping smoking if their partner kept smoking.
  • If their partner became more physically active 66% of women and 67% of men also became more physically active, compared to 24% of women and 26% of men becoming more active if their partner remained inactive.
  • If their partner lost weight 36% of women and 26% of men also lost weight, compared to 15% of women and 10% of men if their partner did not lose weight.

Having a consistently healthy partner also increased the likelihood that a person would stop smoking or become more active, but not the likelihood of losing weight. For all three behaviours, having a partner who changed to a healthier behaviour was associated with a greater likelihood of a person themselves changing behaviour than having a partner with consistently healthy behaviour. The impact of a partner’s behaviour was limited to that specific behaviour (e.g. smoking, or activity, or weight loss) and was not associated with changes in other behaviours in the other partner.

 

How did the researchers interpret the results?

The researchers conclude that “men and women are more likely to make a positive health behavior (sic) change if their partner does too, and with a stronger effect than if the partner had been consistently healthy in that domain”. They suggest that involving partners in programmes aiming to get a person to change their behaviour might improve the outcomes of these programmes.

 

Conclusion

This cohort study has found that individuals with unhealthy behaviours such as smoking, being inactive or being overweight are most likely to change these behaviours if their unhealthy partner also changes these behaviours.

Having a partner who has consistently healthy behaviours was also associated with a greater likelihood of change in smoking and activity compared to a consistently unhealthy partner, but less so than having a partner who changed behaviour.

There were some limitations to the study, including that:

  • The study took into account some confounders, such as age and some health conditions, but other factors could also be having an effect – such as unmeasured health conditions or events. For example, there could have been a mutual life event experienced by both partners that motivated the change, such as the death of a friend or relative from lung cancer leading to quitting smoking.
  • As both partners were assessed at the same time it is not possible to say which person changed first, or whether they both changed together.
  • Smoking and physical activity were reported by the participants themselves and not verified, so may not be accurate.
  • Weight was measured by a nurse and was therefore more likely to be accurate.
  • Behaviours were assessed only twice, either two or four years apart. If a person changed between those assessments but then reverted to their original behaviour this would not have been picked up, and it is not possible to say how long the changes lasted.
  • Results may not apply to younger couples, as the study was restricted to couples with at least one partner aged 50 or over at the start of the study.

It is known that social support from family, friends or other groups can be an important component in people changing their behaviours.

This study supports this concept, and suggests that the impact may be greatest, for partners at least, if that partner is also changing their behaviour.

Our Find Services section can provide details of exercise, stop smoking and weight loss services, many of which are free, in your local area.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Fitness 'rubs off on your partner'. BBC News, January 19 2015

Let’s quit together: health kicks are easier if your partner signs up too. The Guardian, January 19 2015

The best way to get in shape? Get your partner involved: Couples who ditch bad habits are more likely to succeed than those going it alone. Mail Online, January 19 2015

Couples who get fit together more likely to succeed. The Daily Telegraph, January 19 2015

Links To Science

Jackson SE, Steptoe A, Wardle J. The Influence of Partner’s Behavior on Health Behavior Change - The English Longitudinal Study of Ageing. JAMA Internal Medicine. Published online January 19 2015

Categories: NHS Choices

Shell shock remains 'unsolved'

Mon, 19/01/2015 - 10:30

The Mail Online tells us shell shock has been "solved" after scientists claimed they have pinpointed the brain injury that causes pain, anxiety and breakdowns in soldiers.

The Mail's claim is prompted by a study that carried out autopsies on five military veterans who had a history of blast exposure to see what type of brain damage this might have caused.

Four out of five of these people showed signs of what is called diffuse axonal injury, where there is damage to the long nerve fibres that carry electrical signals throughout the brain. This nerve fibre damage seemed to have accumulated in "honeycomb" patterns.

However, we cannot conclude with any degree of certainty that blast injury was the direct and only cause of this damage, as these results are clouded by several factors.

Three of the five veterans died from an opiate overdose. People without a military background who died from an overdose also showed this nerve fibre damage, as did people who had suffered other types of brain injury, such as from a traffic accident – albeit without the honeycomb pattern.

This means it is difficult to know how much other factors contributed to this nerve fibre damage. In short, shell shock has not been "solved", as the Mail Online would have us believe.

 

Where did the story come from?

The study was carried out by researchers from the Johns Hopkins University School of Medicine in the US.

Funding was provided by the Johns Hopkins Alzheimer's Disease Research Center, the Kate Sidran Family Foundation, and the Sam and Sheila Giller family.

The study was published in the peer-reviewed medical journal, Acta Neuropathologica Communications on an open-access basis, so it is free to read online or download as a PDF.

The Mail Online coverage does not acknowledge that we cannot draw any firm conclusions on cause and effect from the results of this small study.

Claims stating shell shock has been "solved" are simplistic and cannot be supported by the results of such a small study, where multiple confounding factors are involved.

 

What kind of research was this?

This was a laboratory study that aimed to look at the brain changes that may occur from exposure to blast injury during military deployment.

The researchers say there are thought to be 250,000 veterans of conflicts in Iraq and Afghanistan with traumatic brain injury, many resulting from a blast.

This a complex form of injury said to incorporate "the direct effects of overpressure wave (primary injury), the gunshot-like effects of debris and shrapnel showering the head (secondary injury), the fall impact from translocation of the body by the overpressure wave (tertiary injury), as well as flash burns from the intense heat and asphyxiation or inhalation injuries".

Though there is a 100-year history of blast injuries, starting with those resulting from artillery shelling during the First World War, there is still a lack of understanding of the actual physical damage and injury it causes the brain.

Recent animal studies suggest these blasts cause what is called diffuse axonal injury. Diffuse means the injury is spread throughout the brain, rather than being isolated to one specific area.

It usually results from acceleration or deceleration forces moving the brain within the skull, similar to what may occur through vigorous shaking, which causes tearing injuries to the long nerve fibres (axons) that transmit signals throughout the brain.

Diffuse axonal injury is one of the most common types of traumatic brain injury, and effects can range from concussion to coma and death. 

This study conducted autopsies of veterans who had a history of blast injury to see whether there was any evidence of diffuse axonal injury.

 

What did the research involve?

The study included five male veterans with a history of blast injury who died at an average age of 28. Three died from an opiate or alcohol overdose. Similarly aged control subjects used as a comparison included:

  • six people who died from an opiate overdose (four females, two males)
  • six people who died from a lack of oxygen to the brain (three males, three females)
  • five people who died from another type of traumatic brain injury, such as falls or road traffic accidents (all male)
  • seven people who died with no history of traumatic brain injury, overdose or oxygen starvation

The researchers carried out brain autopsies on these people, particularly looking for evidence of amyloid precursor protein (APP), which is said to accumulate when there is diffuse axonal injury.

 

What were the basic results?

The researchers found four out of five of the blast injury cases showed evidence of APP accumulation in the nerve fibres in various parts of the brain, most predominantly in the frontal area.

These areas of damage were described to have formed into irregularly shaped "honeycomb" patterns.

The one person who did not show these abnormalities was said to have died from a gunshot wound to the head, and had a history of exposure to several IED attacks.

Three out of four of these cases with APP accumulation in the nerve fibres died from an opiate overdose. When compared with six non-military people who also died from opiate overdose, five of these controls were also found to have a few APP abnormalities, but they were significantly fewer in number.

Also, compared to the war veterans, none of these controls displayed the same "honeycomb" distribution of nerve fibre damage. 

In the controls who also died from traumatic brain injury, but not military related, these people showed quite a different pattern of nerve fibre damage from both the veterans and those who had died from an opiate overdose.

Their nerve fibre abnormalities tended to be "thick with prominent undulations and bulbs", while the non-military controls who died from an opiate overdose tended to have thin, straight abnormalities.

The controls who died as a result of a lack of oxygen to the brain showed quite variable APP accumulation – two showed APP abnormalities, four did not.

The controls without any history of traumatic brain injury, oxygen starvation or overdose did not show any APP abnormalities at all.

 

How did the researchers interpret the results?

The researchers say that: "Our findings demonstrate that many cases with history of blast exposure are featured by APP [nerve fibre damage] that may be related to blast exposure, but an important role for opiate overdose, [lack of oxygen to the brain before death], and concurrent blunt traumatic brain injury events in war theatre or elsewhere cannot be discounted."

 

Conclusion

This research aimed to shed light on the type of brain damage that blast exposure during military conflict may cause.

Previous research suggested blast exposure can cause diffuse axonal injury, where the forces acting upon the brain cause tearing and damage of the long nerve fibres that connect different parts of the brain.

This study found some supportive evidence suggesting this might be the case. Four of the five veterans with a history of blast injury did show this type of nerve fibre damage.

Researchers also observed a distinctive "honeycomb" pattern of nerve fibre damage, which was not present in other controls.

However, it cannot be concluded with much certainty that blast injury was the direct and only cause of this damage, as these results are clouded by several factors. Three of these five veterans died from an opiate overdose.

Non-military people who also died from an overdose still showed this nerve fibre damage, albeit in a different pattern. Similarly, people who suffered other types of traumatic brain injury also had this type of nerve fibre damage, though again with a different pattern.

Therefore, as the researchers acknowledge, it is difficult to rule out the influence that opiate overdose, lack of oxygen to the brain around the time of death, and other non-blast trauma may have had upon these brain changes in this military sample.

It is also not known whether these nerve fibre injuries had any effect on the person's subsequent health and brain function, or whether the injury was related to their cause of death in any way.

This is likely to depend on the severity of the brain damage: as is already recognised, diffuse axonal injury can encompass a wide extent of brain damage, from mild concussion to death.

The reliability of this study's conclusions would be improved if the results were replicated in a larger number of people, or in studies that better accounted for the wide range of other confounders (such as associated injuries or causes of death) that could explain the difference observed.

Although this study is of interest, the small sample sizes examined here – both the military personnel and the various control groups – make it difficult to draw any firm conclusions about the type of damage and subsequent health effects that may result from blast injuries during military conflict.

If you serve, or have served, in the armed forces and think your experiences have taken a psychological toll, there is help and support available. Read more about accessing healthcare for military personnel and veterans.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Shell shock solved: Scientists pinpoint brain injury that causes pain, anxiety and breakdowns in soldiers. Mail Online, January 16 2015

The mystery of shellshock solved: Scientists identify the unique brain injury caused by war. The Independent,  January 15 2015

Links To Science

Ryu K, Horkayne-Szakaly I, Xu L, et al. The problem of axonal injury in the brains of veterans with histories of blast exposure. Acta Neuropathological Communications. Published online November 25 2014

Categories: NHS Choices

Could 'DNA editing' lead to designer babies?

Mon, 19/01/2015 - 09:54

"Rapid progress in genetics is making 'designer babies' more likely and society needs to be prepared," BBC News reports.

The headline is prompted by advances in “DNA editing”, which may eventually lead to genetically modified babies (though that is a very big “may”).

The research in question involved the technique of intacytoplasmic sperm injection (ICSI), where a mouse sperm cell was injected into a mouse egg cell. At the same time, they injected an enzyme (Cas9) capable of cutting bonds within DNA, alongside “guide” RNA to guide the enzyme to its target location in the genome. This system then “cut out” targeted genes.

So far, the techniques have only been tested in animals and for “cutting out” very specific genes (currently, under UK law, any attempt to modify human DNA is illegal).

Although this is very early stage research, the potential uses could be vast. They range from arguably more “worthy” uses, such as editing out genes linked to genetic conditions such as cystic fibrosis, to opening up the possibility for a whole manner of cosmetic or “designer” uses – such as choosing your baby’s eye colour.

Such a possibility is always going to be controversial and lead to much ethical debate. As the researchers say, the possibility that these findings could one day lead to similar tests using ICSI techniques in human cells suggests that it is time to start giving this careful consideration.

 

Where did the story come from?

The study was carried out by researchers from the University of Bath and was funded by the Medical Research Council UK and an EU Reintegration Grant.

The study was published in the peer-reviewed scientific journal Scientific Reports. The study is open access, so it is free to read online or download as a PDF.

The BBC accurately reports this study, including quotes from experts about the possible implications.

 

What kind of research was this?

This was laboratory and animal research, which aimed to explore whether the DNA of mammals can be “edited” around the time of conception.

The researchers explain how recent study has developed the use of an enzyme that cuts bonds within DNA (Cas9). This enzyme is guided to its target location in the genome by “guide” RNA (gRNA). To date, the Cas9 system has been used to introduce targeted DNA mutations into various species including yeast, plants, fruit flies, worms, mice and pigs.

In mice, Cas9 has been used successfully to introduce mutations in single-cell embryos, called pronuclear embryos. This is the stage where the egg has just been fertilised and the two pronuclei – one from the mother and one from the father – are seen in the cell. Such early targeting of the embryo’s genome directly leads to an offspring with the introduced genetic mutation.

However, it is unknown whether Cas9 and gRNA could be used to introduce genetic change immediately before the pronuclei are formed (that is, when the sperm cell is fusing with the egg cell, but before the genetic material from the sperm has formed the paternal pronucleus). Therefore, in this study, the researchers aimed to see whether it was possible to use Cas9 to edit the paternal mouse DNA immediately following ICSI. 

 

What did the research involve?

Briefly, the researchers collected egg cells and sperms cells from 8-12 week old mice. In the laboratory, the sperm were injected into the egg cells using the ICSI technique.

The Cas9 and gRNA system was used to introduce targeted gene mutations. This was tried in two ways: firstly, by a one-step injection, where the sperm cell was injected in a Cas9 and gRNA solution; and secondly, where the egg cell was first injected with Cas9 and then the sperm was subsequently injected in a gRNA solution.

The sperm cell that they used had been genetically engineered to carry a certain target gene (eGFP). They were using the Cas9 and gRNA system to see whether it could “edit out” this gene. Therefore, the researchers examined the subsequent stages of blastocyst development (a mass of cells that develops into an embryo) to see whether the system had introduced the required genetic change.

They followed the studies targeting eGFP with studies targeting naturally occurring genes.

Resulting embryos were transferred back to the female to grow and develop.

 

What were the basic results?

Following ICSI, around 90% of fertilisations developed to the blastocyst stage.

When the researchers first carried out a fertilisation using the male sperm that had been genetically engineered to carry the eGFP gene, about half of the resulting blastocysts had a functioning copy of this gene (i.e. they made the eGFP protein). When the sperm were simultaneously injected with the Cas9 and gRNA system to “edit” this gene, none of the resulting blastocysts showed a functioning copy of this gene. 

When they next tested the effect of pre-injecting the egg cell with Cas9, and then injecting the sperm cell with gRNA, they found that this was also effective at editing the gene. In fact, subsequent tests showed that this sequential method was more effective at “editing” than the one-step injection method.

When the eGFP gene was introduced into the egg cell rather than the sperm, and then the Cas9 and gRNA system introduced in the same way, only 4% of the resulting blastocysts demonstrated a functioning copy of this gene.

When next testing the naturally occurring genes, they chose to target a gene called Tyr because mutations to this gene in black mice resulted in a loss of pigment to the coat and eyes. When the Cas9 and gRNA system was similarly used to target this gene, loss of pigment was transmitted to the offspring.

 

How did the researchers interpret the results?

The researchers conclude that their experiments show that injecting egg cells with sperm, along with Cas9 and guide RNA, “efficiently produces embryos and offspring with edited genomes”.

 

Conclusion

This laboratory research using sperm and egg cells from mice demonstrates the use of a system to produce targeted alterations in the DNA – a process the media like to call “genetic editing”. The editing happened just before the genetic material of the egg and sperm cell fuse together.

The system makes use of an enzyme (Cas9) capable of cutting bonds within DNA, and a “guide” molecule targeting it to the correct genetic location. So far, the techniques have only been tested in animals, and for “editing out” a small number of genes.

However, though this is very early stage research, the results do unavoidably lead to questions about where such technology could lead. ICSI techniques are already widely used in the field of assisted human reproduction. ICSI is where a single sperm is injected into the egg cell, as in this study, as opposed to in vitro fertilisation (IVF), where an egg cell is cultured with many sperm to allow fertilisation to take place “naturally”.

Therefore, the use of ICSI makes it theoretically possible that this study may one day lead to similar techniques being possible to edit the human DNA around the time of fertilisation and so prevent inherited diseases, for example.

As the research importantly states: “this formal possibility will require exhaustive evaluation”.

Such a possibility is always going to be controversial and lead to much ethical and moral debate over whether such steps are “correct” and where they could possibly then lead to (such as altering other non-disease aspects of inheritance, like personal traits).

As one of the lead researchers reports to BBC News, extreme caution will be needed with any further developments. However, they consider that the time is right to think about this, as it is an issue that the UK’s Human Fertilisation and Embryology Authority (HFEA) – the body that monitors UK research involving human embryos – is likely to have to face at some point.

While the possibility of DNA editing in humans may seem like the stuff of science fiction, our Victorian ancestors would have felt the same way about organ transplants.

A spokesman for the HFEA is quoted in BBC News as saying: “We keep a watchful eye on scientific developments of this kind and welcome discussions about future possible developments…It should be remembered that germ-line modification of nuclear DNA remains illegal in the UK”. They say that new legislation would be needed from Parliament “with all the open and public debate that would entail” for there to be any change in the law.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

'Designer babies' debate should start, scientists say. BBC News, January 19 2015

Links To Science

Suzuki T, Asami M, Perry ACF. Asymmetric parental genome engineering by Cas9 during mouse meiotic exit. Scientific Reports. Published online December 23 2014

Categories: NHS Choices

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